Template:On this day/May 21
- 1888 – Western end of Santa Rosa Island (Punta de Sigüenza) was transferred to U.S. War Department by Executive Order.
- 1973 – Daniel "Chappie" James, Jr. was promoted to lieutenant general, then the highest ranking African-American in the U.S. military.
- 1999 – Vanette Webb was suspended from the Escambia County School Board by Governor Jeb Bush.
- 2008 – Groundbreaking for the new Lucia M. Tryon Branch Library on Langley Avenue took place.