Which theme best describes american history until 1877

Manifest Destiny

Explanation:

 is a phrase and idea that expresses the belief that the United States of America is a nation destined to expand from the Atlantic coasts to the Pacific. This idea is also used by supporters to justify other territorial acquisitions. The supporters of this ideology believe that the expansion is not only good, but also obvious (manifest) and accurate. This ideology could be summarized in the phrase: "By the Divine or God's Authority".

The phrase happened to become a doctrine over time.

From this assumption, the United States annexed the territories of Texas (1845), California (1848) and invade Mexico (1846), in what would be the Mexico-United States war. As a consequence, the United States appropriated Colorado, Arizona, New Mexico, Nevada, Utah and parts of Wyoming, Kansas and Oklahoma, in total 2 million 100 thousand square kilometers - 55% of the Mexican territory of that time -, which is he called it "the Mexican Assignment." In return, the United States pledged to pay $ 15 million.