In Roosevelt’s time, before the days of the river commission, it must have been still more difficult to comprehend.  Nevertheless, the information he collected, satisfied him that the stream was navigable for steamers, and his report determined his partners to build the pioneer craft at Pittsburg.  She was completed, “built after the fashion of a ship with portholes in her side,” says a writer of the time, dubbed the “Orleans,” and in 1812 reached the city on the sodden prairies near the mouth of the Mississippi, whose name we now take as a synonym for quaintness, but which at that time had seemingly the best chance to become a rival of London and Liverpool, of any American town.  For just then the great possibilities of the river highway were becoming apparent.  The valley was filling up with farmers, and their produce sought the shortest way to tide-water.  The streets of the city were crowded with flatboatmen, from Indiana, Ohio, and Kentucky, and with sailors speaking strange tongues, and gathered from all the ports of the world.  At the broad levee floated the ships of all nations.  All manual work was done by the negro slaves, and already the planters were beginning to show signs of that prodigal prosperity, which, in the flush times, made New Orleans the gayest city in the United States.  In 1813 Jackson put the final seal on the title-deeds to New Orleans, and made the Mississippi forever an American river by defeating the British just outside the city’s walls, and then river commerce grew apace.  In 1817 fifteen hundred flatboats and five hundred barges tied up to the levee.  By that time the steamboat had proved her case, for the “New Orleans” had run for years between Natchez and the Louisiana city, charging a fare of eighteen dollars for the down, and twenty-five dollars for the up trip, and earning for her owners twenty thousand dollars profits in one year.  She was snagged and lost in 1814, but by that time others were in the field, first of all the “Comet,” a stern-wheeler of twenty-five tons, built at Pittsburg, and entering the New Orleans-Natchez trade in 1814.  The “Vesuvius,” and the “AEtna.”—­volcanic names which suggested the explosive end of too many of the early boats—­were next in the field, and the latter won fame by being the first boat to make the up trip from New Orleans to Louisville.  Another steamboat, the “Enterprise,” carried a cargo of, powder and ball from Pittsburg to General Jackson at New Orleans, and after some service on southern waters, made the return trip to Louisville in twenty-five days.  This was a great achievement, and hailed by the people of the Kentucky town as the certain forerunner of commercial greatness, for at one time there were tied to the bank the “Enterprise” from New Orleans, the “Despatch” from Pittsburg, and the “Kentucky Elizabeth” from the upper Kentucky River.  Never had the settlement seemed to be so thoroughly in the heart of the continent.  Thereafter river steamboating grew so fast that by