File:Panama Canal Div. SSI.jpeg Authorized in 1920, the Panama Canal Division of the United States Army was organized in 1921 in order to insure the United States could adequately defend the Canal Zone (similar divisions were organized to defend Hawaii and the Philippines). Its initial composition included the 19th Infantry Brigade (14th and 65th Infantry Regiments, of which the 65th was stationed in Puerto Rico) and the 20th Infantry Brigade (33rd and 42nd Infantry Regiments). The two brigades appear to have been active until 1927. (McGrath, 'The Brigade,' p. 166)