The existence of Harmon Air Force Base in Stephenville impacted on the area quite significantly socially. In 1941, when the base was constructed, there was a tremendous population boom in the area. In the census of 1857, there were 107 residents; in 1874, 268 residents; and 1901, 643 residents. With the construction of the base in 1941, however, the population exploded to over 7,000 virtually overnight.

The base created new opportunities in all social contexts. The original residents of the area were occupied with farming and fishing. During the construction and operation of the base, however, significant numbers of Newfoundlanders were employed as tinsmiths, sheet metal workers, construction laborers, carpenters, etc... The new occupational opportunities offered people totally new ways of life and impacted tremendously on previously established social norms.

Transportation linkages such as the railway and sea port were developed with areas where previously no linkages existed. Social infrastructures such as the hospital offered people benefits previously unavailable. Although the closing of the base in 1966 caused an economic blow to the area, the infrastructure left behind by the Americans became the foundation of Stephenville's subsequent prosperity.

The social impact of the base can also be measured in very human terms. Many long-lasting friendships were developed as a direct result of the base and interaction between military personnel and civilians. The existence of the base played a large part in the significant numbers of marriages that occurred between Americans and Newfoundlanders. In a social context, this very personal interaction resulted in both positive and negative circumstances. Also, the human cost of airplane crashes such as the one that occurred at Crash Hill on October 3, 1946, will forever be a part of the social heritage of Harmon Air Force Base and Stephenville.