Explain what is meant by manifest destiny and describe how belief in that idea was the main reason that the u. s going to mexico

In the 1840s, the U. S was struck with the idea of manifest destiny. An idea that America should control North America from the Atlantic Ocean to the Pacific Ocean. Mexico had the legal right to Texas thus dominated California, Arizona, and New Mexico. Two territories stood in America's way of accomplishing the manifest destiny idea; first, the Oregon Territory that was occupied by both Great Britain and the United States and the Western and Southwestern areas owned by Mexico. The differences between the United States and Mexico over the border of Texas led to the Mexican American War that resulted in American gaining ownership of Arizona, California, New Mexico, and Texas. The ownership of these territories fulfilled the 'Manifest Destiny' of the U. S stretching from the Atlantic to the Pacific, Manifest Destiny.

The manifest destiny was the belief held by the United States' citizens in 1845 that they were destined by God to expand its dominion and spread capitalism and democracy accross the entire North America continent, spanning from Atlantic Ocean to the Pacific Ocean. Thus, they went to war with Mexico in 1846 gaining half of Mexican territory, including lands from Texas to California. So, the United States obeying its Manifest destiny, encompassed land from Atlantic Ocean to the Pacific Ocean.