The McAdam Post Office is recognized for its connection to noted architect Thomas W. Fuller and its role in the McAdam community.

The McAdam Post Office was one of several post offices across the country erected as part of a project by the Canadian Federal Government to increase their presence in small towns across the country. These buildings were designed by Thomas W. Fuller, Chief Dominion Architect for the Government of Canada from 1927 to 1936. Taking inspiration from the work of his father Thomas Fuller Sr., who was Chief Dominion Architect from 1881 to 1896, Fuller crafted these buildings to showcase features from both the Gothic Revival and Romanesque Revival styles. These offices were characterized by their picturesque massing, accented by stone gables. However, possibly due to the economic hardship brought on by the Great Depression, this particular building is noticeably scaled down in comparison to its predecessors, lacking the clock towers that were present in much of Fuller's previous work.

The building was operated by the federal government for many years, at times also hosting a Customs and Immigration Office and the RCMP. In the present, though no longer under the ownership of the government, the building continues to function as a post office and a community hub.