Ayer's history dates back to 1667 when the first mill, used to grind corn in the agricultural community of South Groton, was built. 

Originally part of the town of South Groton, Ayer was incorporated in 1871 and named in honor of Dr. James Cook Ayer, a prominent resident of Lowell who provided the funding for the construction of Town Hall (1873-76). 

Growth was influenced by the industrial age and the rapid development of railroad transportation in New England. Though only 9.5 square miles in area the town became a major junction for both east-west and north-south rail lines due to its central location. This all helped Ayer develop into a vital commercial center.

The Civil War brought another ingredient to Ayer. An army training camp, originally named Camp Stevens, was located on land donated by Ayer, Shirley and Harvard near the Nashua River. This small mustering depot eventually became Camp Devens, and continued to grow during WWI  to become a major base for training and embarkation of troops heading over to Europe. 

Fort Devens, as it was now known, and the presence of thousands of military and civilian support personnel on the base shifted Ayer's commercial development towards meeting their needs until 1994 when Fort Devens was eventually caught up in federal base closures..

Ayer today is a town struggling to define itself. No longer supported by a military economy it has experienced a recent period of uncertainty. 

Ayer  boasts numerous industries, including the areas Pepsi bottler and Cain mayonnaise plant. A unique, main street U.S.A. flavor remains in the thriving, historical downtown. 

Located in North Central Massachusetts Ayer is situated on Rt. 2 and Rt. 2A only minutes from Rt. 495. Commuter rail service puts Boston within a 50 minute train ride .