In the 1920s, Charles Richard Shannon demolished an old house on this site and erected a new building to serve as the town’s post office. Apartments were housed on the second floor. His son, James Shannon became the Postmaster for the town of Mt. Jackson soon after this and served until 1970. A local legend claims the building was constructed in exchange for his appointment, though there is no evidence to collaborate this.
James’s tenure, interrupted only by his military service from May 1944- December 1945, was the longest of any local postmaster. When he was originally appointed, local postmasters were still chosen by the President of the United States who picked people according to their political allegiance. However Franklin Roosevelt altered this system during his Presidency and Shannon was able to remain postmaster despite political changes.
During the late 20th century, the post office in town had reached a crossroads. The Shannon building was no longer suitable for postal operations which had out grown the first floor space available to it. Eventually land was acquired on the north end of town and a new post office was constructed there in 1998. Today the building houses apartments and a first floor commercial space.