During WWII, the east and west coasts of the United States were protected by civilian volunteer aircraft spotters, members of the Ground Observer Corps. The GOC was a component of the Aircraft Warning Service (AWS) that was established in May 1941 in response to the development of heavy bomber aircraft capable of flying over 1,000 miles to keep watch for enemy planes entering American airspace. It became inactive on May 29, 1944. Almost one million men and women volunteer “soldiers out of uniform” served in the AWS. In 1942, it became one of Merchantville's most popular outdoor sports with many teachers from Merchantville High School volunteering for tours of duty at a post located on Kresson Lake in Burlington County.