Abraham Lincoln was issued a patent for his invention to lift boats over shoals and other obstructions in a river.
As a teenager the future President had taken a flatboat along the Ohio and Mississippi Rivers. After moving to Illinois he was employed by Denton Offutt a merchant and owner of a general store, to ferry goods along the Mississippi and its tributaries.
During these river trips Lincoln’s boats had run aground on more than one occasion, leading to the exhausting process of freeing the boat before it sank or the cargo went overboard. These experiences were to provide the inspiration for his invention.
Lincoln is believed to have begun work on his device in 1848, in which ‘adjustable buoyant air chambers’ attached to the boat could be forced under the water and inflated to float the boat free of the obstruction without the need to unload any of the cargo. He filed an application to the Patent Office on 10 March 1849, and Patent No. 6469 was awarded two months later on 22 May.
A model of the device is said to have been produced with the assistance of Walter Davis, a mechanic from Springfield, although Paul Johnston from the National Museum of American History believes it may instead have been made in Washington. Whatever the truth behind the creation of the model, this is the furthest that Lincoln’s invention ever got since nobody ever tried to install the system on a full-size boat.
The model itself can be seen on display at the Smithsonian Institute, and is claimed by the curator of the Marine Collection to be ‘one of the half dozen or so most valuable things in our collection.’ The invention is also significant in that it makes Abraham Lincoln the only President in the history of the United States to have been awarded a patent.