Complex sentence: George Dewey was promoted to Admiral of the Navy on March 24,1903, retroactive to March 2,1899, and the Navy Department declared the 1944 5 star rank rank of Fleet Admiral to be junior to Dewey's rank.
Split into simpler sentences: George Dewey was promoted to Admiral of the Navy on March 24,1903, retroactive to March 2,1899. In 1944 the Navy Department declared the newly created 5 star rank rank of Fleet Admiral to be junior to Dewey's rank.