Loading view. There were no results found. There were no results found. Prince William County Fairgrounds Events Venues Prince William County Fairgrounds 10624 Dumfries Rd Manassas, 20112 United States Get Directions (703) 368-0173 Events at this venue Today Upcoming Upcoming Select date. Previous Events Today Next Events Subscribe to calendar Google Calendar iCalendar Outlook 365 Outlook Live Export .ics file Export Outlook .ics file