Fort Devens opens in Ayer, Harvard, and Shirley.

(Sept.) Originally Camp Devens, it is built at a rate of about 10 barracks a day between June and September 1917. First used as a training camp, it processes more than 100,000 soldiers during World War I. It is renamed when it becomes a permanent US Army post in 1931. It process more than 600,000 soldiers during World War II, when nearly 65,000 people live or work on the base. Used to process thousands more soldiers for the Korean, Vietnam, and early Middle East conflicts. The camp is decommissioned in 1996 and subsequently transformed into residential, office, industrial, and retail uses.