Abraham Lincoln

Thomas Jefferson usually gets credited as America’s inventor-in-chief, but Abraham Lincoln is the only president to hold a U.S. patent. In 1849, shortly after the end of his lone term as a U.S. congressman, the Great Emancipator was issued U.S. Patent No. 6,469 for a device for “Buoying Vessels Over Shoals.” Lincoln had come up with the idea a year earlier after watching crewmen try to free a steamboat that had run aground on the Detroit River. Upon returning home to Illinois, he drew up plans for a pair of buoyant air chambers that could be attached to the sides of a boat and used to lift the vessel over shallow sections of river. Lincoln spent several weeks writing a description of the device and even built a scale wooden model, but while he received his patent, the invention was never put to use.