Next came the patent laws. These began in England in 1624, and in this country with the adoption of our Constitution. Before then any man [might] instantly use what another man had invented, so that the inventor had no special advantage from his invention. The patent system changed this, secured to the inventor for a limited time exclusive use of his inventions, and thereby added the fuel of interest to the fire of genius in the discovery and production of new and useful things.

Abraham Lincoln, from the lecture on “Discoveries, Inventions, and Improvements,” delivered in 1859 and 1860.

Lincoln is the only U.S. President to hold a patent (U.S. Patent No. 6,469). During his career as a lawyer he represented clients in several patent lawsuits.