Prince William County Detention 14873 Dumfries Rd Manassas, VA 20112 Phone : (703) 791-3181 Business Category Government Offices-County Legislative Bodies Prince William County Of--manassas, Juvenile Detention Center Manassas, VA 20112 Phone : (703) 791-3181 Business Category Government Offices-County Government Offices & Public Schools Prince William County Government--eastern District Office-social Services, Juvenile Detention Manassas, VA 20112 Phone : (703) 791-3181 Business Category Government Offices-County Government Offices & Public Schools