The Confederates used Using the Potomac ’ s banks as gun positions Placing to halt Union traffic on the river , protecting Defending Manassas Junction to the west and Fredericksburg to the south and to close Process_end the Potomac River to shipping Sending and isolate Hindering Washington .

The First Battle of Bull Run ( the name Name_conferral used Using by Union forces ) , also known as the First Battle of Manassas ( the name Name_conferral used Using by Confederate forces ) , was the first major battle Hostile_encounter of the American Civil War and was a Confederate victory Earnings_and_losses .

The battle Hostile_encounter was fought Hostile_encounter on July 21 , 1861 in Prince William County , Virginia , just north of the city of Manassas and about 25 miles west-southwest of Washington , D.C .

Gen. P. G. T. Beauregard camped near Manassas Junction .