July 11, 1840
Military conflict between the United States of America and Mexico from 1846 to 1848
1840 United States presidential election — 14th quadrennial U.S. presidential election
Indigenous Australian Frontier War
1840 battle between Zulu factions
Battle in February 1840
1840 siege during the Russo-Circassian War
1840 battle between China and Britain
1840 treaty leading to the Oriental Crisis
1840 battle between Egypt and the Ottoman Empire
1840 treaty between the United States and Miami