Answer: Abraham Lincoln

While Abraham Lincoln will always be best known as a man of humble birth who rose to the highest office in the land (and had an incredibly influential role on the course of the United States during very turbulent times), that doesn’t mean he didn’t have a little time along the way during his early political career to make history of a different sort—patenting an invention.

In 1849, Lincoln filed a patent for a device inspired by both his work and travels on river boats. Boats would frequently become stuck on shoals and obstructions in murky water and he came up with a design that would outfit boats with large bladders on the sides, such that the bladders could be inflated to raise the bottom of the boat above the obstruction.

What makes this patent notable isn’t that the design came to fruition (and, to be honest, there are doubts as to whether it would have actually worked), but that it is the only patent issued to a U.S. president.