John Philip Sousa was the leader of the United States Marine Band from 1880 to 1892. He was an American composer and conductor, known as 'The March King' for his military marches. He wrote more than 130 marches, including 'The Stars and Stripes Forever'. He also wrote many other works, including operettas and suites of music. He was a major influence on American music, and his works are still popular today.