1803 treaty between the United States and Native Americans

Louisiana Purchase — 1803 acquisition by the U.S. of France's claim to the territory of Louisiana

1803 naval battle between the United States and the Tripoli Eyalet

1803 marked the opening shots of the Blockade of Saint-Domingue

1803 treaty between the United States and the Kaskaskia

1803 treaty between the United States and Choctaw

1803 battle of the Second Anglo-Maratha War

1803 battle of the Second Anglo-Maratha War

1803 major battle of the Second War of Haitian Independence

1803 battle of the Second Anglo-Maratha War

1803 treaty between Great Britain and Maratha