- May 1, 1898 – Battle of Manila Bay: U.S. Navy defeats Spanish fleet during the Spanish-American War.
- May 5, 1961 – Alan Shepard becomes the first American in space aboard Freedom 7.
- May 7, 1915 – Sinking of the Lusitania by a German U-boat; pushes U.S. closer to WWI.
- May 10, 1869 – Transcontinental Railroad completed at Promontory Point, Utah.
- May 17, 1954 – Brown v. Board of Education ruling ends racial segregation in public schools.
- May 20, 1927 – Charles Lindbergh departs for the first solo nonstop transatlantic flight.
- May 25, 1961 – JFK announces goal to land a man on the Moon before the decade’s end.
