The Treaty of Guadalupe hidalgo was established in the war between the United States and Mexico. It was signed on February 2, 1848 and has been treated in the ancient past that is still in effect between the United States and Mexico. As a result of the treaty, the United States acquired more than one million two hundred thousand square kilometers of valuable territory and emerged as a world power at the end of the nineteenth century.
In the 1850s, reformers also came to power in Mexico and promised to strengthen the country's political system so as not to be more victims of US aggression. The reform of Benito Juarez ( President at the time) was the beginning of a process of political and economic modernization that continues to the present in Mexico.
cause of tension was that the Soviet Union was trying to spread communism. The U.S. was against communism and they took leadership of containment policy. The Containment policy was the U.S. approach to trying to prevent communism spreading.