John L. O'Sullivan devised the term manifest destiny in 1840’s in place of a growing belief that the United States was destined by God to expand. The idea that the United States had a God given right to expand its territory was used to justify territorial growth and conquest of the west. The term manifest destiny didn’t just become a catch phrase which justified American efforts to conquer new territory but also to seek out new markets for its goods across the oceans. Manifest destiny was a defense of what is now called Imperialism. The settlers from the United States that gradually moved into the Mexican province of Texas was one of the clearest examples of manifest destiny in the nineteenth century. A series of reactions led to the annexation