Building on his talent for song-writing, Root moved to Chicago, Illinois in 1859 to work for his brother's music publishing house of Root & Cady. He became particularly successful during the American Civil War, as the composer of martial songs such as "Tramp! Tramp! Tramp!" (The Prisoner's Hope), "The Vacant Chair" (with lyrics by Henry S. Washburn), "Just before the Battle, Mother", and "The Battle Cry of Freedom". He wrote the first song concerning the war, "The First Gun is Fired", only two days after the conflict began with the bombardment of Fort Sumter. He ultimately had at least 35 war-time "hits", in tone from the bellicose to the ethereal. His songs were played and sung at both the home front and the real front. "Tramp, Tramp, Tramp" became popular on troop marches, and "Battle Cry of Freedom" became well-known even in England.