Mexican American War
April 21, 1836: A New Country is Formed - The Republic of Texas: Texas used to be a state in Mexico, the Mexican State of Texas. Texas fought Mexico for independence and won! Texas became a country, the Republic of Texas.
Border Skirmishes: There was a great deal of disputed territory that Texas insisted was part of Texas. Mexico insisted it belonged to Mexico. There were constant border skirmishes.
1845: Texas becomes the 28th US State: To solve things, Texas asked to be annexed into the United States. Texas believed joining with the United States would end their battle with Mexico.
1846-48, The Mexican-American War: Still, border skirmishes continued. This was a major cause of the Mexican-American war, a war America won. The battle cry, “Remember the Alamo” rang out again.
It was an important war because it changed the shape of both Mexico and the United States. Here is a quick and interactive story of this war and its outcome: Mexican American War interactive
See Also: The Alamo