1821 treaty between the United States and representatives of the Odawa, Ojibwe, and Potawatomi peoples

Treaty between the United States and Spain, ceding Florida to the U.S. (1819)

First battle of the Italian unification process ("Risorgimento")

Battle on 8 April 1821

1821 siege by the Greek rebels during the early days of the Greek War of Independence

1821 battle between Greeks and Ottomans in the Acropolis of Athens

1821 battle of the Greek War of Independence

1821 battle during the Greek War of Independence

1821 battle of the Greek War of Independence

1821 battle that occurred during the Greek War of Independence

Battle during the Greek War of Independence