Had it not been for the building of the railroads in the 1840s, Ayer may not have been established. Originally called South Groton, the town thrived as tanneries, vinegar factories, sawmills, and other industries settled in the area. The rapid economic development and population growth led to the formation of the Town of Ayer in 1871, named for Dr. James Cook Ayer, a producer of hair tonic and patent medicines who had donated money to the town. Ayer thrived, becoming a rail hub for transporting goods and passengers. In 1917, the War Department leased local land to build a new Army training...