Despite the road improvements of the turnpike era(1790—1830), Americans continued as in colonial times to depend wherever possible on water routes for travel and transportation. The larger rivers, especially the Mississippi and the Ohio, became increasingly useful as steamboats grew in number and improved in design. River boats carried to New Orleans the corn and other crops of northwestern farmers, the cotton and tobacco of southwestern planters. From New Orleans, ships took the cargoes on to eastern sea ports. Neither the farmers of the west nor the merchants of the east were completely satisfied with this pattern of trade. Farmers could get better prices for their crops if the alternative existed of sending them directly eastward to market, and merchants could sell larger quantities of their manufactured goods if these could be transported more directly and more economically to the west. New waterways were needed. Sectional jealousies and constitutional scruples stood in the way of action by the federal government, and necessary expenditures were too great for private enterprise. If extensive canals were to be dug, the job would be up to the various states. New York was the first to act. It had the natural advantage of a comparatively level route between the Hudson River and Lake Erie, through the only break in the Appalachian Mountain chain. Yet the engineering tasks were imposing. The distance was more than 350 miles, and there were ridges to cross and a wilderness of woods and swamps to penetrate. The Erie Canal, begun in 1817 and completed in 1825, was by far the greatest construction job that Americans had ever undertaken. It quickly proved a financial success as well. The prosperity of the Erie encouraged the state to enlarge its canal system by building several branches. The range of the New York canal system was still further extended then the states of Ohio and Indiana, inspired by the success of the Erie Canal, provided water connections between Lake Erie and the Ohio River. What does the passage suggest was the principal route for transporting crops to the east prior to 12?