The March Composer John Philip Sousa was a famous American composer and conductor of the late 19th and early 20th centuries. He is best known for his military marches, which include 'The Stars and Stripes Forever' and 'The Liberty Bell'. He wrote over 130 marches during his career, and was known as 'The March King'. He also composed operettas, waltzes, and other works. He was a major influence on the development of American music, and his works remain popular today.