"If you happened to find yourself on the banks of the Ohio River on a particular afternoon in the spring of 1806—somewhere just to the north of Wheeling, West Virginia, say—you would probably have noticed a strange makeshift craft drifting lazily down the river. At the time, this particular stretch of the Ohio, wide and brown and bounded on both sides by steep shoulders of land thick with oaks and hickories, fairly boiled with river traffic, as a ramshackle armada of keelboats and barges ferried settlers from the comparative civilization of Pennsylvania to the wilderness of the Northwest Territory.
The peculiar craft you'd have caught sight of that afternoon consisted of a pair of hollowed-out logs that had been lashed together to form a rough catamaran, a sort of canoe plus sidecar. In one of the dugouts lounged the figure of a skinny man of...