Manifest Destiny was an idea that implied that the United states had the divine right (i.e. the God-given right) to expand to the Pacific Ocean. The central idea of this position was that the US had a divine right to spread across the continent of North America and into the Pacific Ocean. A newspaper man named John L. O'Sullivan first used the term in 1845. President James K. Polk ran on a platform of what would be called Manifest Destiny. A belief in Manifest Destiny led to the U.S. fighting the Mexican-American War. It involved convincing Americans that the reason it was okay to fight, kill take the land from Mexicans or other non-Americans, was because God (or possibly the spirit of "Columbia") wanted them to cause this suffering. This belief continued to play a key role in the United States settlement of western lands, especially in the rush to California and in the U.S. taking over Oregon.