I can only think he meant to say the Treaty of Guadalupe Hidalgo (1848).
The Treaty of Guadalupe Hidalgo (Tratado de Guadalupe Hidalgo in Spanish), officially entitled the Treaty of Peace, Friendship, Limits and Settlement between the United States of America and the Mexican Republic,[1] is the peace treaty signed on 2 February 1848, in the Villa de Guadalupe Hidalgo (now a neighborhood of Mexico City) between the U.S. and Mexico that ended the Mexican–American War (1846–48).
With the defeat of its army and the fall of the capital, Mexico entered into negotiations to end the war. 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 gave the United States the Rio Grande boundary for Texas, and gave the U.S. ownership of California, and a large area comprising New Mexico, Arizona, Nevada, Utah, and parts of Wyoming and Colorado. Mexicans in those annexed areas had the choice of relocating to within Mexico's new boundaries or of receiving American citizenship with full civil rights. Over 90% chose the latter.
The U.S. Senate ratified the treaty by a vote of 38–14. The opponents of this treaty were led by the Whigs, who had opposed the war and rejected Manifest Destiny in general, and rejected this expansion in particular.[2]
and it seems to have no bearing to the conversation