One by one the other important centers of trade in the great valley beyond began to show evidences of life. Marietta, Ohio, founded in 1788 by Revolutionary officers from New England, became the metropolis of the rich Muskingum River district, which was presently sending many flatboats southward. Cincinnati was founded in the same year as Marietta, with the building of Fort Washington and the formal organization of Hamilton County. The soil of the Miami country was as "mellow as an ash heap" and in the first four months of 1802 over four thousand barrels of flour were shipped southward to challenge the prestige of the Monongahela product. Potters, brickmakers, gunsmiths, cotton and wool weavers, coopers, turners, wheelwrights, dyers, printers, and ropemakers were at work here within the next decade. A brewery turned out five thousand barrels of beer and porter in 1811, and by the next year the pork-packing business was thoroughly established.
Louisville, the "Little Falls" of the West, was the entrepôt of the Blue Grass region. It had been a place of some importance since Revolutionary days, for in seasons of low water the rapids in the Ohio at this point gave employment to scores of laborers who assisted the flatboatmen in hauling their cargoes around the obstruction which prevented the passage of the heavily loaded barges. The town, which was incorporated in 1780, soon showed signs of commercial activity. It was the proud possessor of a drygoods house in 1783. The growth of its tobacco industry was rapid from the first. The warehouses were under government supervision and inspection as early as 1795, and innumerable flatboats were already bearing cargoes of bright leaf southward in the last decade of the century. The first brick house in Louisville was erected in 1789 with materials brought from Pittsburgh. Yankees soon established the "Hope Distillery"; and the manufacture of whiskey, which had long been a staple industry conducted by individuals, became an incorporated business of great promise in spite of objections raised against the "creation of gigantic reservoirs of this damning drink."
Thus, about the year 1800, the great industries of the young West were all established in the regions dominated by the growing cities of Pittsburgh, Cincinnati, and Louisville. But, since the combined population of these centers could not have been over three thousand in the year 1800, it is evident that the adjacent rural population and the people living in every neighboring creek and river valley were chiefly responsible for the large trade that already existed between this corner of the Mississippi basin and the South.