WHo is John lo' Sullivan?

John L. O'Sullivan was a 19th-century American journalist and editor best known for coining the term "Manifest Destiny" in 1845. This concept articulated the belief that the expansion of the United States across the American continents was both justified and inevitable. O'Sullivan's ideas played a significant role in shaping American attitudes toward westward expansion and the annexation of territories such as Texas and Oregon. His writings reflected the era's views on nationalism and Imperialism.