Delegate Mossburg was educated at Puritan Christian School in Laytonsville, MD.
Mossburg was a one-term delegate from the heavily Democratic Montgomery County, Maryland.
District 39, in 1994, was fully Republican with Mossburg, W. Raymond Beck, and Barrie S. Ciliberti.
However, Maryland Governor Parris Glendening redrew many districts in the Democrats' favor.
Though his original map was redrawn by the court system, Republicans suffered with all three in this district losing in the 1998 election.