The complex of ideas associated with the concept of the Manifest Destiny of the United States is best described as the notion of its quasi-divine mission of territorial expansion (Expansionism) and of the history of the United States as the fulfillment of that mission. John L. O'Sullivan, a New York journalist and politician of the Democratic Party, coined the phrase in an 1845 essay in the periodical he edited, the United States Magazine and Democratic Review: “our manifest destiny to ov…