A large scale Sepoy Revolt, which started in Meerut and other Indian Army barracks in north-central India, triggered the Indian Mutiny against British rule. (By Brian Bockelman)

A dispute over a nominally "British" vessel sailing in Chinese waters leads to the second Anglo-Chinese War (1856-58), a struggle over the opium trade and Britain's commercial presence in Asia. (By Brian Bockelman)

Congress declared that "a state of war exists" between the U.S. and Mexico, blaming the Mexicans for attacking American forces in disputed Texas border areas.