Portal:United States/Anniversaries/August/August 21
- 1680 – Pueblo Indians capture Santa Fe from the Spanish during the Pueblo Revolt.
- 1778 – American Revolutionary War: British forces begin besieging the French outpost at Pondichéry.
- 1831 – Nat Turner leads black slaves and free blacks in a rebellion in Southampton County, Virginia, which will claim the lives of 55 to 65 whites and about twice that number of blacks.
- 1883 – An F5 tornado strikes Rochester, Minnesota, leading to the creation of the Mayo Clinic.
- 1959 – United States President Dwight D. Eisenhower signs an executive order proclaiming Hawaii the 50th state of the union. (state flag pictured) Hawaii's admission is currently commemorated by Hawaii Admission Day.
- 2017 – A solar eclipse traverses the continental United States.