what is manifest destiny?

Manifest Destiny was the 19th-century belief in the United States that it was the divine right and destiny of the country to expand its territory westward across the North American continent, from the Atlantic Ocean to the Pacific Ocean. The term was first used by John L. O'Sullivan, a newspaper editor, in 1845 to justify the annexation of Texas and protest European interference. This belief held that such expansion was God-ordained and inevitable, and it significantly influenced U.S. political, social, and cultural development during that period. Manifest Destiny led to large territorial acquisitions through events like the Mexican-American War and sparked conflict over issues such as the displacement of Native Americans and the expansion of slavery, which contributed to the U.S. Civil War.