In 1840 Chicago had been an unimportant settlement of 4500 persons, but by the opening of the war it had grown to twenty-five times that size, and added 800,000 between 1870 and 1890. It had early become evident that the city was the natural outlet toward the East for the grain trade and the slaughtering and meatpacking industry of the upper Mississippi Valley. Before the late sixties, however, railway connection was defective, being composed of many short lines rather than of one continuous road, so that freight had to be loaded and unloaded many times during its passage to the seaboard. This situation, which had been merely inconvenient before the war, had become little short of intolerable during the struggle, because the closing of the Mississippi had cut off from the Middle West its water outlet toward the South and had diverted more freight to the railroads. After the war, Cornelius Vanderbilt, president of the Hudson River Railroad, combined a number of the shorter roads so as to give uninterrupted communication between Chicago and New York, to tap the trade of the Mississippi Valley, and to compete with water traffic by way of the Great Lakes and the Erie Canal. Other railroads saw the possibilities in the western trade, and the Baltimore and Ohio, the Grand Trunk, and the Erie followed the lead of Vanderbilt. A similar development, although on a smaller scale, accompanied the growth of other northern cities. The retroactive effects of the roads on the distribution of the population are too detailed for discussion, but a single example may typify many. In 1870 the Maine farmer supplied much of the meat consumed in Boston; by 1895, he was getting his own meat from the West. He must, therefore, adapt himself to the new conditions if he could, move to the manufacturing cities as so many of his neighbors did, or migrate to the West.