Manassas (mənăs´əs), town (1990 pop. 27,957), seat of Prince William co., N Va., in a farm area; inc. 1873, rechartered 1938. Manassas has become a growing residential town with retail shopping centers; its development has been spurred as the Washington, D.C., suburbs expand further into northern Virginia. There is a large computer memory chip plant, and Internet-related companies are based nearby. The Old Town district contains turn-of-the-century brick buildings. During the Civil War, Manassas was a key railroad junction, and the battles of Bull Run were fought nearby; the sites are locally marked. The town of Manassas Park (1990 pop. 6,734) is adjoining, and near both is the Manassas National Battlefield Park (see National Parks and Monuments, table).