The All of Mexico Movement, or All Mexico Movement, was a political movement to expand the United States to incorporate all of Mexico.[1] It was a controversial aspect of Manifest Destiny that was unable to garner enough political support to encourage adoption. The Mexican-American War (1846–1848) brought the United States and Mexico into conflict over various geopolitical issues, including a desire to invade and annex much of Mexico, that resulted in victory for the United States.
After the US Army took Mexico City, there was renewed enthusiasm for incorporating all of Mexico. There was fierce opposition to the idea within the U.S. Congress on various internal political disputes. The USA army found themselves into a guerrilla warfare situation in Tamaulipas and between Veracruz and Mexico City, making it impossible for the USA to take any effective control of Mexico, and losing men, supplies and military equipment. While the USA forces in Tamaulipas tried to subjugate the local population trough violence and terror, in Mexico City and Vercruz, they tried to respect and not interfere with the local population. Both approaches failed and it was only because of the uprise of more rebel groups that the Mexican elite saw the need to get into an agreement, while for the USA army it was urgent to getting out of the conflict and take as much territory of Mexico as possible without risking more loses.