While the South was producing staples for an ever-growing market, it became itself the market for the surplus products of the Northwest. An active internal trade sprang up between the sections in spite of the natural barriers to commercial intercourse. Live stock could be driven to market. It was a common occurrence to see droves of thousands of "razor-back" hogs on their way from Kentucky to the Seaboard States, feeding on nuts and roots by the way. Rivers were the chief highways for such produce as could not provide for its own locomotion. The Western waters floated all sorts of craft, from the lumber raft to the flatboat, laden with pork, cheese, butter, flour, corn, and whiskey. The greater part of these boats were makeshifts, and made no return voyage. It was not until 1809 that a barge was warped upstream from New Orleans to Nashville. The entire traffic on the Mississippi and the Ohio was carried on until 1817 in less than a score of keel boats, which made the voyage downstream from Louisville to New Orleans in about forty days, and upstream in ninety. When, then, a steamboat succeeded in making a return voyage in twenty-five days, it was hailed as an epoch-making performance. In the next year twenty steamboats were competing for the river traffic; and three years later (1820) seventy-two were in actual service. Yet the steamboat did not drive the flatboat from the Western rivers. So late as 1840 one fifth of the freight handled on the lower Mississippi was carried in flatboats or barges. The rapid rise of this internal commerce between the farmer of the Northwest and the cotton planter of the South increased the ability of both to purchase manufactures in the Eastern markets. Both sections had wants which they could not supply by their simple household industries. They had to import not only their farming implements, but most of those articles, useful or ornamental, which were thought indispensable to a higher civilization. "Spots in Tennessee, in Ohio, and Kentucky," comments an English traveler, "that within the lifetime of even young men, witnessed only the arrow and the scalping knife, now present the traveler with articles of elegance and modes of luxury which might rival the displays of London and Paris." Most of this stock was transported over the mountains from Philadelphia or Baltimore. In 1820, three thousand wagons carried to Pittsburg, the distributing center of the West, nearly eighteen million dollars' worth of merchandise.