Others joined in this opposition, from ignorance of the great commerce growing up on the lakes; and frequently, where bills have been passed by Congress, Southern influence has caused the Executive to veto them. In spite of all these obstacles, however, this great interest forced itself upon the attention of the country; and in July, 1847, a Convention, composed of delegates from eighteen States, met in Chicago, to concert measures for obtaining from Government the necessary improvements for Western rivers and harbors. This body sent an able memorial to Congress, and the result has been that larger appropriations have since been made. Still, however, much remains to be done, and it appears by the last Report of Colonel Graham, that his estimates for necessary work on lake harbors and roadsteads amount to nearly three millions of dollars, to which half a million should be added for the improvement of St. Clair flats, making an aggregate of three and a half millions of dollars, which is much needed at this time, for the safe navigation of the lakes. It may be remarked, in tins connection, that the lakes, with their tributary streams, are furnished with nearly a hundred light-houses, four or five of which are revolving, and the remainder fixed lights,--Lake Ontario having eight, Lake Erie twenty-three, Lake St. Clair two, Lake Huron nine, Lake Michigan thirty-two, and Lake Superior fourteen. When we say that Chicago exports thirty millions of bushels of grain, and is the largest market in the world, many persons doubtless believe that these are merely Western figures of speech, and not figures of arithmetic. Let us, then, compare the exports of those European cities winch have confessedly the largest corn-trade with those of Chicago. 1854. Bushels of Grain. Odessa, on the Black Sea, 7,040,000 Galatz and Bruilow, do., 8,320,000 Dantzic, on the Baltic, 4,408,000 Riga, do., 4,000,000 St. Petersburg, Gulf of Finland, 7,200,000 Archangel, on the White Sea, 9,528,000 ---------- 40,496,000 Chicago, 1860, 30,000,000 or three-quarters of the amount of grain shipped by the seven largest corn-markets in Europe; and if we add to the shipments from Chicago the amount from other lake-ports last year, the aggregate will be found to exceed the shipments of those European cities by ten to twenty millions of bushels. Will any one doubt that the granary of the world is in the Mississippi Valley? The internal commerce of the country, as it exists on the lakes, rivers, canals, and railroads, is not generally appreciated. It goes on noiselessly, and makes little show in comparison with the foreign trade; but its superiority may be seen by a few comparisons taken from a speech of the Hon. J.A. Rockwell, in Congress, in 1846. In the year 1844, the value of goods transported on the New York Canals was..... $92,750,874