The Wilmot Proviso was designed to eliminate slavery in lands acquired by the Mexican War (1846-48). Shortly after the war began, President James K. Polk sought $2 million in a bill to negotiate the terms of a contract. For fear of… The U.S. Senate approved and approved the ratification of the treaty by 38 votes to 14. Opponents of the treaty were led by the Whigs who had opposed the war and who, in general, refused the obvious fate and opposed in particular to this enlargement. The amount of land gained by the United States of Mexico was further increased by the purchase of Gadsden in 1853, which had ceded parts of southern Arizona and New Mexico to the United States. The treaty helped end the civil war in both Mexico and the United States.
In Mexico, it has left many citizens uncertain about the future of their country as an independent state; Political extremism followed and a civil war broke out at the end of 1857. The extension of slavery to the United States had been settled by the Missouri Compromise (1820), but the addition of the huge Mexican wing as a new American territory opened the question. Attempts to settle resulted in the turbulent compromise of 1850 and the Kansas-Nebraska Act (1854). Some Eastern Democrats have called for the total annexation of Mexico and said that some Mexican liberals would support this. but President Polk`s State of the Union address in December 1847 confirmed Mexico`s independence and argued in detail that the occupation and all other military operations in Mexico were aimed at securing a contract to resign from California and New Mexico until the 32nd parallel North and possibly from Baja California and transit rights via the Isthmus of Tehupecante.  The treaty expanded the choice of U.S. citizenship to Mexicans in newly acquired territories, before many African-Americans, Asians and Indians came into play. If they decided, they had to declare to the U.S. government, within one year, that the contract had been signed; Otherwise, they could remain Mexican citizens, but they would have to move. Between 1850 and 1920, the census counted most Mexicans as « white » racially.  Yet racist tensions continued after the annexation, reflected in things like the Greaser Act in California, when suddenly tens of thousands of Mexican nationals found themselves within the borders of the United States.
Mexican communities remained de facto separated from and within other American communities and continued in the southwest through Mexican migration until the end of the 20th century. [Citation required] Trist sent a copy with the fastest means available in Washington, forcing Polk to decide whether or not he wanted to reject the highly satisfying manual labor of his discredited subordinate. Polk decided to send the contract to the Senate.