[4] In 1935, Moncure won election to the Virginia General Assembly (a part-time position) to succeed Herring as the delegate for Stafford and Prince William Counties (as the district was then called).
He won re-election unopposed numerous times, but announced his retirement after the end of the 1959 session on April 4, 1959, during the state's Massive Resistance crisis as explained below.
[5] This measure delayed school integration in Arlington, which finally occurred (peacefully as in Norfolk) in February 1959, after both a three-judge federal panel and the Virginia Supreme Court declared the Stanley Plan of measures supporting continued racial segregation of Virginia's schools (which Moncure staunchly supported), unconstitutional on January 19, 1959.
After his political retirement, Moncure practiced law with his son Thomas, who also served as Stafford County's Commissioner of Accounts for 37 years.
[6] Frank Moncure (like several other Dixiecrats) had supported Dwight Eisenhower for President in 1952 and T. Coleman Andrews and the State's Rights ticket in 1956.
[9][10] From 1982 until 1987, his grandson Thomas McCarty Moncure Jr., who had become a lawyer like his father and grandfather, was elected to the Virginia General Assembly as the delegate representing Stafford County and parts of Fredericksburg.