The site has also been the location of major military celebrations. In May 1865, the Army of the Potomac and the Army of the Tennessee marched along Pennsylvania Avenue in a "Grand Review" before newly-sworn President Andrew Johnson in celebration of the end of the American Civil War. More than 200,000 soldiers passed in review. The procession was so massive it took two full days for both armies to pass. Admiral George Dewey, hero of the Battle of Manila Bay during the Spanish–American War, also led a parade up the avenue in 1899 after the United States' victory in that conflict. General John J. Pershing led the American Expeditionary Force in review up Pennsylvania Avenue in 1919 after the conclusion of World War I.