On May 24, 1932, U.S. Patent No. 1,859,624, issued to Leroy R. Grumman on Retractable Landing Gear.

On May 23, 1905, U.S. Patent No. 790,537 issued to Emmie Alice Thayer and Emily Wailee Thayer on a Mirror Support.

On May 22, 1849, U.S. Patent No. 6,469 issued to Abraham Lincoln on a Manner of Buoying Vessels.

On May 21, 1940, U.S. Patent No. 2,201,689, issued to Water E. Disney on the Art of Animation.

On May 20, 1873, U.S. Patent No. 139121 issued to Jacob W. Davis on Fastening Pocket-Openings (using rivets).

On May 19, 1896, U.S. Patent No. 560,351 issued to Martin Goetze on a Device for Producing Dimples.

On May 18, 1869, U.S. Patent No. 90,298 issued to Francis Peters and George Clem on Improvements in Privy-Seats.

On May 17, 1955, U.S. Patent No. 2,708,656 issued to Enrico Fermi and Leo Szilard on a Neutronic Reactor.

On May 16, 1933, U.S. Patent No. PP65 issued to Luther Burbank on a Rose.

On May 15, 1945, U.S. Patent No. 2,376,028 issued to Leo F. Buck on a Pig Racing Apparatus.