On this day in history, the U.S. and Mexico signed the treaty that ended the Mexican-American War (1846-1848). The treaty is the oldest treaty still in force between the United States and Mexico. As a result of the treaty, the United States acquired more than 500,000 square miles of valuable territory and emerged as a world power in the late nineteenth century.
The treaty called for the United States to pay $15 million to Mexico and pay off the claims of American citizens against Mexico up to $3.25 million. It also gave the U.S. more than 500,000 square miles of valuable territory including ownership of California, and a large area comprising New Mexico, Arizona, Nevada, Utah, and parts of Wyoming and Colorado.
Lincoln had been among the Congressmen who objected to The Mexican War as an unjustified act, challenging President Polk for proof of his insistence that the war began when Mexicans shed American blood on American soil, an assertion Lincoln denied. Lincoln voted for a resolution that declared the war unnecessary and accused Polk of violating the Constitution in commencing it. But in this era, the doctrine of “Manifest Destiny” ruled the day; Lincoln was fighting a losing battle. In any event, Lincoln did vote to supply the American army and he did not support legislation that would have prohibited acquiring territory from Mexico as part of a peace settlement.
For Mexico, The Treaty of Guadalupe Hidalgo ensured that Mexico would remain an underdeveloped country well into the twentieth century. In addition, the treaty had important implications for the civil and property rights of former Mexican citizens in the ceded territories. The treaty promised U.S. citizenship to former Mexican citizens, but the Native Americans in the ceded territories who in fact were Mexican citizens, were not given full U.S. citizenship until the 1930s. In addition, the former Mexican citizens were discriminated against by the U.S. settlers who moved into the new territories, and their rights were not universally upheld in U.S. courts. Within a generation the Mexican-Americans became a disenfranchised, poverty-stricken minority.