While little improvement had been made in water-travel, every increase of distance added to the difficulties of the westward journey. The settler who after buying wagon and horses hauled his family and goods across the mountains, might buy or build a broad flat-bottomed ark, to float with him and his fortunes down the Ohio, in constant peril of upsetting or of being sunk; but only light boats with strong oars could mount the stream, or boats forced against the current by laboriously poling in shallow water. If he carried his tobacco and wheat down the Mississippi to the Spanish port of New Orleans, and sold it, he might return to his home in Kentucky or Ohio by a long and dangerous journey on horseback through the Indian country from Natchez to Nashville, or he might take ship to Philadelphia, if a ship were about to sail, and again cross the Alleghanies. Compared with river travel, the sea was commonly an easy and safe highway. Nearly all the rivers which penetrated the interior were unsure, liable to be made dangerous by freshets, and both dangerous and impassable by drought; yet such as they were, these streams made the main paths of traffic. Through the mountainous gorges of the Susquehanna the produce of western New York first found an outlet; the Cuyahoga and Muskingum were the first highway from the Lakes to the Ohio; the Ohio itself, with its great tributaries the Cumberland and the Tennessee, marked the lines of western migration; and every stream which could at high water float a boat was thought likely to become a path for commerce. As General Washington, not twenty years earlier, hoped that the brawling waters of the Cheat and Youghiogheny might become the channel of trade between Chesapeake Bay and Pittsburg, so the Americans of 1800 were prepared to risk life and property on any streamlet that fell foaming down either flank of the Alleghanies. The experience of mankind proved trade to be dependent on water communications, and as yet Americans did not dream that the experience of mankind was useless to them.