Truly, there were snails in those days.
The river's earliest commerce was in great barges--keelboats, broadhorns.

They floated and sailed from the upper rivers to New Orleans, changed cargoes there, and were tediously warped and poled back by hand.

A voyage down and back sometimes occupied nine months.

In time this commerce increased until it gave employment to hordes of rough and hardy men; rude, uneducated, brave, suffering terrific hardships with sailor-like stoicism; heavy drinkers, coarse frolickers in moral sties like the Natchez-under-the-hill of that day, heavy fighters, reckless fellows, every one, elephantinely jolly, foul-witted, profane; prodigal of their money, bankrupt at the end of the trip, fond of barbaric finery, prodigious braggarts; yet, in the main, honest, trustworthy, faithful to promises and duty, and often picturesquely magnanimous.
By and by the steamboat intruded.

Then for fifteen or twenty years, these men continued to run their keelboats down-stream, and the steamers did all of the upstream business, the keelboatmen selling their boats in New Orleans, and returning home as deck passengers in the steamers.
But after a while the steamboats so increased in number and in speed that they were able to absorb the entire commerce; and then keelboating died a permanent death.