The most important port of entry in these harbors is _New York_, and it derives its importance from two factors. It has a very capacious harbor, into which vessels drawing as much as thirty-five feet may enter; its situation at the lower end of a series of valleys and passes makes it almost a dead level route from the Mississippi to the Atlantic seaboard. The importance of New York as the commercial gateway between European ports and the food-producing region of the American continent began when the Erie Canal was opened between the Great Lakes and tide-water. The completion of the canal for the first time opened the rich farming lands of the interior to European markets. Probably a greater tonnage of freight is carried yearly over this route than over any other channel of trade in the world. Not far from two-thirds of the foreign commerce of the country passes through the port of New York. The water-front of the city has an aggregate length of about three hundred miles, of which one-third is available for anchorage. The docks and piers, including those of Jersey City and Hoboken, aggregate about ninety miles in frontage. About sixteen thousand sea-going craft enter and clear yearly, and an average of nearly twenty large passenger and freight steamships arrive and clear daily, about one-half of them being foreign. The latter receive their cargoes from about three thousand freight-cars that are daily switched into the various freight-yards, a large part of which is through freight from the west. The port of entry of _New York_ is a centre of population of about four million, and although there are the industries usually found in great communities, the greater business enterprises practically reduce themselves to export, import, and exchange. For this reason New York City is the financial, as well as the commercial centre of the continent. Most of the great industrial corporations of the country have their head offices in the city. These are financed by more than one hundred banks, together with a clearing-house whose yearly business amounted in 1902 to considerably more than seventy billions of dollars.[50] [Illustration: BOSTON HARBOR] _Boston_ has been one of the leading ports of the United States for considerably more than a century. It ranks second among the ports of the United States. Regular lines of transit connect it with the principal ports of Great Britain and Canada. The coast trade is also very heavy. Boston is the financial and commercial centre of New England; the cotton, woollen, and leather goods passing through the port find their way to nearly every inhabited part of the world. The city controls a considerable export trade of food-stuffs from the upper Mississippi Valley. The vessels entering and clearing at Boston indicate a movement of about four million five hundred thousand tons, about one-fourth that of New York. The clearing-house exchanges average about six billion dollars yearly.