Today in History, May 22, 1849:
“Be it known that I, Abraham Lincoln, of Springfield, in the county of Sangamon, in the state of Illinois, have invented a new and improved manner of combining adjustable buoyant air chambers with a steam boat or other vessel for the purpose of enabling their draught of water to be readily lessened to enable them to pass over bars, or through shallow water, without discharging their cargoes;”
Young Abraham Lincoln receives patent #6469 for an invention to lift river boats over shoals and other obtructions.
Among many other jobs he’d held, he had hauled freight on flat boats on the Mississippi. Twice his boat was hung up. As was common, once the boat had to be unloaded, repaired and portaged over the obstruction…a very laborous job.
Lincoln’s invention would inflate bladders to create more boyancy, lifting the craft over the problem. His invention was never put into use, so it’s viability remains unproven. It does make Abe the only US President with a patent.