What did John J O Sullivan write an influential editorial on?

John L. O'Sullivan wrote an influential editorial in 1845 that articulated the concept of "Manifest Destiny," the belief that the United States was destined to expand across the North American continent. In his piece, he argued that it was America's divine right and duty to spread its institutions and culture westward. O'Sullivan's editorial helped to galvanize public support for westward expansion, shaping American policy and attitudes toward territorial acquisition during that era.