Second Army Corps (Spanish–American War) about one month. The number of deaths and at Thoroughfare Gap was 34. Only two brigades of the 2d Army Corps saw combat in the Spanish–American War. They left for Santiago de Cuba to reinforce Gen. Shafter's army. An armistice having been reached between the U.S. and Spain ending the war’s fighting on August 12, 1898. The Separate Brigade, 3rd Division 2d Army Corps, under command of Brigadier General Henry M. Duffield, left Camp Alger June 15, 1898. They soon saw action in the Battle of the Aguadores, Cuba. After which the brigade was transferred to the Fifth Army Corps
Siege of Santiago along San Juan Heights. In the charge at the Battle of San Juan Hill U.S. forces captured the Spanish position. At the Battle of El Caney the same day, U.S. forces took the fortified Spanish position and were then able to extend the U.S. flank on San Juan Hill. The destruction of the Spanish fleet at the Battle of Santiago de Cuba allowed U.S. forces to safely besiege the city. On July 3, 1898, the same day as the naval battle, Major General William "Pecos Bill" Shafter began the siege of Santiago. Shafter fortified his position on San Juan Heights.