1776 After the United States became independent, it took advantage of the opportunity of European powers to compete for colonies in Africa and Asia and expanded in the North American continent. 1823, President james monroe put forward the slogan "America is American America" and established the basic national policy of expanding territory and dominating America. Soon, the aggressive eyes of the US government fell on neighboring Mexico.

1846 in may 13, the us government declared war on Mexico, and the us-Mexico war officially broke out.

1September 847 15, Mexico city fell, and the heroic and unyielding Mexican people launched a large-scale guerrilla war with the occupiers. In desperation, the US military mobilized 20,000 people to fight guerrilla warfare and brutally suppressed the resistance of the Mexican people. 1848 On February 2, the United States and Mexico signed the Treaty of Guadalupe Hidalgo. The United States seized nearly half of Mexico's territory, totaling about 2.3 million square kilometers. This is most of California, Nevada, Utah, Arizona and New Mexico, as well as parts of Colorado and Wyoming. The United States only paid Mexico $654.38+05 million as "compensation".

Through the US-Mexico War, the United States became a powerful country across the Atlantic Ocean and the Pacific Ocean, and has since become the master of the United States. Even Grant, a famous American who took part in the war personally, had to admit: "This war is one of the most unjust wars waged by powerful countries against weak countries."