Future President Abraham Lincoln was granted Patent No. 6,469, on May 22, 1849, for a device called "Buoying Vessels Over Shoals". This invention was a method of lifting boats over shallow water, which was inspired by a trip to Niagara Falls where Lincoln witnessed a boat getting stuck.
Lincoln's device used expandable bellows attached to the sides of a boat. These bellows would be inflated to lift the boat over shoals or obstructions. Lincoln was 40 years old at the time. He remains the only U.S. president to ever receive a patent. More
