U.S. Patent No. 6,469 begins thusly:
“Be it know 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.”
Yes, that Abraham Lincoln. Patent #6469 is the only patented ever granted to a U.S. President. (Though Lincoln was not president at the time he was granted the patent.)
Waterman, Patent Lawyer, President
Before he became perhaps the GOAT Commander in Chief, Abraham Lincoln worked as a patent lawyer for several years. Before that, he worked a variety of jobs that took him between his home in Illinois and New Orleans via river.
Whilst traveling on the Sangamon River on one such job, the flatboat on which Lincoln was riding got hung up on a milldam and started to sink. Lincoln quickly sprang into action, ditching some of the boat’s cargo into the river to right it, then drilling a hole in the deck to drain the accumulated water. He then plugged the hole, portaged around the milldam with help from the locals, and completed his trip down to New Orleans in the repaired boat.
A few years later, Lincoln made his first foray into politics. One of his first platforms was improving the navigability of the Sangamon River. Another boat he was traveling on during this period became stranded on a shoal, and was only dislodged after a considerable amount of elbow grease was applied by all aboard. This, coupled with the previous incident, inspired Lincoln to create his patented invention.
Whatever Floats Your Boat, Abe!
Looking for a way to lift vessels over shoals and other obstructions in waterways, Lincoln invented an inflatable flotation device that could be attached to the hull of a boat. Comprised of a series of waterproof fabric bladders, the device would be inflated when needed to ease a stuck ship over obstacles. In theory, the air chambers would lift the watercraft above the surface of the water, giving it enough clearance to avoid getting stuck.
Lincoln designed and, with the help of Walter Davis, a Springfield, Illinois, mechanic, built a scale model of a ship outfitted with his device. The model is currently on display at the Smithsonian Institution. Lincoln was awarded his patent on 22 May 1849, shortly after the conclusion of his two-year term in the U.S. House of Representatives.