The extension of the Lewis and Clark Trail from St. Louis all the way to Pittsburgh is an invitation for all of us to reboot our understanding of the Lewis and Clark Expedition. The late Stephen Ambrose deserves credit for giving ample space to the Ohio River portion of the transcontinental journey in “Undaunted Courage” and for penning a sentence that has been much reproduced in Lewis and Clark literature, especially by those who wish to bring greater prominence to the Eastern Legacy: “When they shook hands, the Lewis and Clark Expedition began.”

In most editions of the journals, the expedition begins at St. Charles, Mo., on May 14, 1804. This is true of Bernard DeVoto’s influential 1953 edition of “The Journals of Lewis and Clark,” Elliott Coues’ “The History of the Lewis and Clark Expedition” (1893), John Bakeless’ “The Journals of Lewis and Clark” (1964) and Frank Bergon’s “The Journals of Lewis and Clark” (1989). St. Charles is also the starting point in Gary Moulton’s one-volume digest, “The Lewis and Clark Journals: An American Epic of Discovery” (2003) and his more recent narrative, “The Lewis and Clark Expedition: Day by Day” (2018).

Historians have been more willing than editors (who are always fighting page length) to discuss the Ohio River journey as part of their overarching narrative of the expedition. Most historians see the Ohio segment as a kind of shakedown cruise for what was to follow in the spring of 1804: the mustering of the watercraft, the historic meeting of the captains at the Falls of the Ohio, the preliminary gathering of the crew (a mustering ritual in the manner of the film “The Dirty Dozen”), mastering baggage distribution in the boats and recognizing the unwieldiness of the keelboat. Paul Russell Cutright includes a chapter entitled “Potomac to Wood River” in his monumental “Lewis and Clark: Pioneering Naturalists” (1969) and David J. Peck includes one entitled “‘Misqutrs’ on the Ohio,” in his” Or Perish in the Attempt: Wilderness Medicine in the Lewis and Clark Expedition” (2002). David Lavender includes a chapter called “Trial Run” in “The Way to the Western Sea: Lewis and Clark Across the Continent” (1998).

The Ohio segment takes on added importance because it is our introduction to the mercurial and fascinating commander of the expedition, Meriwether Lewis. Lewis was almost entirely silent during the first full year of travel, May 14-Oct. 26, 1804. The narrative of that key segment of the journey — St. Charles to the Mandan villages — belongs entirely to William Clark and the lesser journal keepers. I believe our understanding of the Lewis and Clark story would be significantly different had Lewis been writing at his full power day by day for those 165 days in 1804.

When Lewis was writing — when the switch was on — he was without question the most articulate, insightful, probing, reflective, geopolitical, philosophical and observant of the journal keepers. Fortunately, we get to know Lewis pretty well on the Ohio descent because he is the only voice we have and because he was engaged in what appear to be warm-up exercises for an aspiring Enlightenment explorer.

To get a full picture of Lewis on the Ohio, the eastern journal must be read in close proximity with the letters Lewis wrote to President Jefferson during the same period (July 4-Dec. 1, 1803) and the one that he wrote to William Clark. Lewis wrote to Jefferson from Harper’s Ferry on July 8; from Pittsburgh on July 15 and again on July 22 and July 26; on Sept. 8 from Wheeling; on Sept. 13 from Marietta; and on Oct. 3, from Cincinnati.

We learn in the letters from Pittsburgh that Lewis was by no means sure that William Clark would join him as his “partner in discovery.” In fact, he seems to have thought Clark would not be available. He had not yet received a reply to his beautiful June 19 letter of invitation to Clark. Meanwhile, as backup, Lt. Moses Hooke had agreed to join Lewis on the expedition in a subordinate capacity if Clark declined or if Clark’s response did not arrive before Lewis left Pittsburgh.

Lewis outlined Hooke’s qualifications to President Jefferson in his letter of July 26 and sang his praises: “I might safely calculate on being as ably assisted by him in the execution of the objects of my mission, as I could wish, or would be, by any other officer in the Army.”

Lewis wanted to make sure the War Department (and Jefferson) would approve of Hooke’s participation and process the attendant paperwork, knowing that he (Lewis) would be harder to reach by letter or dispatch once he embarked on the shallow and evaporating Ohio River. He even developed a plan for Hooke to catch up with him at the mouth of the Missouri — by an overland horse ride — if the paperwork did not arrive before Lewis put the keelboat in the river.

Fortunately, a week later, Lewis received Clark’s letter of July 18: “my friend I join with you hand & heart.” Think about it. We may be indebted to the procrastinations of the drunken boat maker of Pittsburgh for William Clark’s participation in what otherwise might be known as the Lewis and Hooke Expedition. If the boat had been ready on time, given Lewis’s characteristic impatience and commitment to mission, he might well have named Hooke his subordinate partner in discovery because he could not afford to embark on the great journey without selecting a second in command.

Once he had heard from Clark, Lewis expressed joy and relief that his old friend would not only join him in what Clark called a “vast, Hazidous and fatiguing enterprize,” but join for the duration of the adventure. Lewis had been so eager to secure Clark’s participation that he had offered him the option of accompanying the exploring party part way and then turning back.

Now that the leadership team was in place, Lewis was mostly concerned that he and Clark recruit the right sort of men for the crew. “I am pleased,” Lewis wrote, “that you have not admitted or encouraged the young gentlemen you mention, we must set our faces against all such applications and get rid of them on the best terms we can. They will not answer our purposes.” What Lewis wanted was “good hunters, stout, healthy, unmarried men, accustomed to the woods, and capable of bearing bodily fatigue in a pretty considerable degree.” No gentlemen’s sons, no individuals who would shun hard physical labor and substantial pain. Lewis also informed Clark that he was trying to secure the services of an interpreter named John Conner, who had “offered himself, by letter, to accompany me.” Lewis and Conner were unable to connect and he did not join the expedition at Kaskaskia or Fort Massac, as Lewis hoped he might. On Sept. 28, Lewis reported that Conner “has decieved me very much,” and therefore “I do not much regret the loss.”

Finally, on Sept. 8, Lewis was able to write to President Jefferson from the road. He was at Wheeling, (West) Va., which had been founded in 1770, four years before Lewis’ birth. In the letter, Lewis explains the “unpardonable negligence” of the boat builder, the consequent delays, and the difficulties of navigating even with the current in low water. Five days later, at Marietta, Lewis wrote a short note to Jefferson providing further details about the difficulty of getting the boats over the Ohio River’s sandbars.

Lewis spent a good deal of time in the course of the expedition worrying about possible congressional criticism of the expedition and of the Jefferson administration. He had, after all, served as Jefferson’s private secretary and aide de camp from April 1, 1801, until July 5, 1803. In addition to listening to Jefferson’s vision of the American West and his desire to put reconnaissance teams along the principal river arteries, to Jefferson’s emerging American Indian policies, to Jefferson’s strategizing about how to keep the Mississippi River open to American commerce and to Jefferson’s plans to wrest some of the northwest fur trade away from Great Britain, Lewis undoubtedly heard Jefferson and Madison discuss politics before, during and after Jefferson’s famous casual dinner parties in the White House.

Lewis had served as a courier and congressional liaison for Jefferson. Since Jefferson refused to deliver annual messages in person, this meant that Lewis carried those important documents to the Capitol on the president’s behalf. He had accompanied Jefferson’s daughters from the near environs of the Federal City to Jefferson’s private quarters in the Executive Mansion and taken them shopping, such as it was, in the District of Columbia. He had handled some of the delicate and potentially explosive negotiations with the scurrilous “journalist” James Callendar, who was blackmailing Jefferson over the Sally Hemings relationship. By the time he lit out for the West, Lewis knew Jefferson’s public and private business about as well as anyone, perhaps better than Jefferson’s best friend, James Madison, who would have been spared some of the less agreeable cogitations of the Sage of Monticello.

Lewis must have believed the Jefferson administration was more vulnerable than, in fact, it was. Lewis was a long way from the capital, but he was still eager to protect his patron Jefferson in any way he could. Accordingly, at the end of his long field report on mammoth bones at Big Bone Lick, Ky., Lewis got ahead of his skis: “As this Session of Congress has commenced earlyer than usual, and as from a variety of incidental circumstances my progess has been unexpectedly delayed, and feeling as I do in the most anxious manner a wish to keep them in a good humour on the subject of the expedicion in which I am engaged, I have concluded to make a tour this winter on horseback of some hundred miles through the most interesting portion of the country adjoining my winter establishment; perhaps it may be up the Canceze River and towards Santafee, at all events it will bee on the south side of the Missouri.” Lewis goes on to say that he  may even instruct Clark “to undertake a similar excurtion through some other portion of the country.”

Jefferson replied Nov. 16, probably instantly if you factor in the pace of the frontier post office at the time. For once he did not couch his intentions in gracious or periphrastic language: “One thing however we are decided in: that you must not undertake the winter excursion which you propose in yours of Oct. 3. Such an excursion will be more dangerous than the main expedition up the Missouri, & would, by an accident to you, hazard our main object, which, since the acquisition of Louisiana, interests every body in the highest degree. The object of your mission is single, the direct water communication from sea to sea formed by the bed of the Missouri & perhaps the Oregon.”

Then, after describing several other exploration projects he has in mind for the Red (Arkansas) and other western rivers, Jefferson reinterates: Lewis’ prime mission is “not to be delayed or hazarded by any episodes whatever.” “Episodes” has a slightly patronizing feel. This is one of the sternest letters Jefferson ever sent to Meriwether Lewis.

With all that as background, what do we learn from the journals about the expedition’s commander Meriwether Lewis during this shakedown tour?

First, that he was an impatient man. The boat maker was a drunk and a procrastinator. He finally finished the expedition’s keelboat a month behind schedule, and only then because Lewis hounded and hectored him and did some of the labor himself. Partly because of that delay, the Ohio River wasn’t really carrying enough water to float the 55-foot keelboat. This made for tedious, exhausting and — Lewis thought — expensive forward progress.

When, after a chance meeting at Wheeling with William Ewing Patterson, who “expressed a great desire to go with me,” the son of Philadelphia’s Robert Patterson did not show up at the appointed time the next day to join the expedition in a medical capacity, Lewis did not linger for another day just in case or (as far as we know) send messengers to investigate the delay.

The next day, Sept. 9, Lewis began his journal entry with, “The Dr. could not get ready  I waited untill thre this evening and then set out.” Even the proposed overland winter excursion to Santa Fe can be seen as a sign of Lewis’ impatience: what am I going to do to occupy my time during the winter while waiting for the river to open?

We also see glimpses of Lewis’ temper. In his letter to Jefferson on Sept. 8, 1803, Lewis explains why he got such a late start from Pittsburgh: “I had been most shamefully detained by the upardonable negligence of my boat-builder …according to his usual custom he got drunk, quarrelled with his workmen, and several of them left him… I threatened him with the penalty of his contract, and exacted a promise of greater sobriety in future which, he took care to perform with as little good faith, as he had in his previous promises with regard to the boat, continuing to be constantly either drunk or sick. I spent most of my time with the workmen, alternately persuading and threatening. …” This is milder than Lewis’ later hissy fit over the evasions of Manuel Lisa: “Damn Manuel and triply Damn Mr. B. [Francois Benoit]. They give me more vexation and trouble than their lives are worth. I have dealt very plainly with these gentlemen, in short I have come to an open rupture with them; I think them both great scoundrels. …”

Second, Lewis was learning to become an Enlightenment explorer. One can especially feel the influence of Thomas Jefferson on this leg of the journey, as if the Enlightenment president’s intellectual gravity was strongest closest to the national capital and to Monticello, or strongest in the relatively uncomplicated early stages of the great journey.

Lewis’ journal during this interlude seems to be designed to please Jefferson, America’s greatest exemplar of the Enlightenment. Lewis speculates on the migratory pattern of Ohio valley squirrels. He spends days trying to describe Ohio River morning fogs accurately and determine their cause. He plays with his new thermometers, taking air and water temperatures (partly to explain the fogs), in a manner that would have pleased the Sage of Monticello, who took weather data virtually every day of his adult life and recorded that data in one of his five daily journals, his meteorological log. Lewis makes observations about the banks and benches and the farther hills of the Ohio and the Mississippi rivers and attempts to determine high water marks, partly with an eye to the siting of future trade and military forts on the frontier. He engages in mineralogical observations and, to some degree, geological. He spends a whole day measuring the giant earth mounds of the Ohio country and speculating on what sort of Natives had civilizations advanced enough to produce them, and just when. At the important confluence of the Ohio and the Mississippi (ca. Nov. 15-19), Lewis and Clark give their combined surveying and latitude-longitude skills a serious workout, ascertaining the width of the Ohio (1,274 yards), the Mississippi (1,435 yards), and recording the latitude as 39.50.00.

The longest single document Lewis created during the Ohio River excursion is his Oct. 3, 1803, epistolary dissertation on Big Bone Lick, Ky. Lewis knew that nothing could please the Enlightenment president more than a shipment of mastodon or mammoth bones from what had already been recognized as one of the best bone fields in America. Lewis visited the site, interviewed the paleontologists who were excavating there, arranged to send boxes of bones to Jefferson and described the contents in significant detail. Unfortunately, the treasury that Lewis arranged to send to Jefferson miscarried. Donald Jackson says they “went astray at Natchez and apparently were lost.”

At the end of this fascinating and scientifically sophisticated letter, Lewis proves his Enlightenment credentials by asking Jefferson to “forward me some of the Vaxcine matter, as I have reason to believe from several experiments made with what I have, that it has lost it’s virtue.” Just whom Lewis had been trying to vaccinate for the smallpox on the Ohio excursion is unclear.

In all of this Meriwether Lewis was practicing being an Enlightenment traveler, making the kind of observations he knew would please Jefferson, the kinds of observations that characterize Jefferson’s early American classic, “Notes on the State of Virginia” (1785). He was earning the famous tribute Jefferson paid to him after his untimely death: “of sound understanding and a fidelity to truth so scrupulous that whatever he should report would be as certain as if seen by ourselves.”

Third, we also get what in retrospect represents an ominous taste of things to come. Lewis writes continuously from Aug. 31 to Sept. 18 (19 days), then abruptly goes silent until Nov. 11 (a total of 54 days). Once he takes up his pen again, Lewis writes every day from Nov. 11 until Nov. 28, when he concludes his 1803 journal with one short sentence: “This morning left Capt. Clark in charge of the Boat.” Thereafter Lewis goes silent, at least with respect to his journal, with a few scattered exceptions, until April 1805.

Thus, if the Eastern Legacy portion of the expedition extends from Aug. 31 at Pittsburgh until Clark landed the three expedition boats at the mouth of Wood River on Dec.12, a total of 103 days, Lewis produced journal entries on 37 of those days, and was silent for 66 days.

Lewis’ silences include the historic meeting with William Clark, his presumed encounter with George Rogers Clark and his introduction to the Nine Young Men from Kentucky and the 10th young man from Kentucky, Clark’s slave York. Clark was not keeping a journal yet, nor were any of the Nine Young Men. Lewis’ historic meeting with William Clark (Oct. 14) is now commemorated with a Clarksville, Ind., statue and other iconography, including a splendid painting by Michael Haynes, featuring a joyful and patriotic  handshake for which there is no documentary evidence (but which surely occurred). But as Stephen Ambrose puts it, “Unfortunately, we don’t have a single word of description of the meeting of Lewis and Clark.” However much we try to explain away Lewis’ silences, they were not only irresponsible. In the course of the expedition, those silences denied us descriptions of great historical importance.

Lewis’ silences are a significant issue, which has not received all of the attention it deserves. Historian David Nicandri has argued that the explorer he is currently studying, Capt. James Cook, would “surely have been court martialed had he returned to Britain without a full and detailed journal.” Thanks to the steadiness and discipline of William Clark, we have a full account of the journey, but as I have argued elsewhere, essential moments of the expedition, when Clark was not at hand with pen and field journal, were never recorded. These include, among others, Lewis’ important diplomatic mission to the Hidatsa villages on Nov. 25-26, 1804; and Lewis’ arrival at the beach of the Pacific Ocean on Nov. 14, 1805.

We also learn a little about Lewis luck. On the very first day of the expedition, Lewis’ airgun was accidentally discharged in the hands of a gentleman stranger to whom Lewis was demonstrating its mechanism. The projectile struck a woman in the head (blood gushed). Lewis, aghast, reported that fortunately she was not mortally wounded. Had this unnamed woman died that day, who knows what might have been the result. It’s hard to believe Lewis would have given up — he was leading a government-sponsored military reconnaissance — but it would have been an exceedingly unpropitious start. He might have been detained, at least briefly, until the matter was resolved. Later in the expedition, Lewis survived a bout of arsenic poisoning (Aug. 22, 1804), a face-to-face encounter with an angry grizzly bear (June 14, 1805), a gunfight with young Blackfeet men (July 27, 1806)  and a nasty flesh wound in the buttocks that could easily have killed or paralyzed him (Aug. 11, 1806).

Finally, we learn a little about William Clark — admittedly by inference. From any rational analysis in retrospect, we know that Clark played an immensely important role in the success of the expedition. In fact, it is possible to argue that without Clark (or someone of his talents and character) it is hard to see how the expedition could have succeeded in full measure, and perhaps not at all. From May 14, 1804, on, Clark became the baseline journal keeper of the expedition. In another hand (Moses Hooke?), the maps of the expedition might have been adequate; Clark’s maps are masterful, almost inspired. Clark’s capacity with the men — especially when a lighter touch of discipline was needed — was clearly superior to Lewis’.

Although he did not share Lewis’ remarkable physical stamina or Lewis’ stoicism in the face of pain and discomfort, Clark seems to have had a higher commitment to the sorts of duties that remain below the line of the heoric. Lewis was happiest on shore with his dog, his rifle and his collection bag. Clark’s solo or near-solo adventures on shore were rare because he accepted as his duty the management of the boats and the men. If to Lewis the great geopolitical and psychological burdens fell, Clark assumed command over the day-to-day business of loading and repairing boats, overseeing forward progress, managing the campsites, and establishing a relaxed but proper set of  protocols.

Above all else, Clark somehow knew how to calm Lewis down, keep his wilder impulses in check, steady him in moments of doubt, balance his temper and his high-handedness. Much is made of the handshake at the Falls of the Ohio. I think it is possible to see this as far more than a warm greeting between old frontier and army friends. At least from retrospect, we should look on this as a passing of at least part of the baton of leadership from Lewis to Clark, and it is quite possible to think of Lewis’ reaction as relief. He was not going to shoulder the burden of exploration alone. He was going to be assisted — reassured, balanced, sometimes even propped up — by someone who had performed that role before — after Lewis’ court martial in 1795. At the moment of the symbolic handshake, in some significant sense Lewis put the success of the mission in William Clark’s hands.

As Clint Eastwood said, “A man has to know his limitations.” In some authentic corner of his being, Lewis did.