DeKalb (dēkălb), city (1990 pop. 34,925), DeKalb co., N Ill., in a farm area; inc. 1861. The city is a distribution center with manufactures that include plastics, electrical equipment, and agricultural silos. There also are agricultural research facilities. The growth of the city was stimulated in the 1870s by the development and manufacture of workable barbed wire by a resident, Joseph F. Glidden. DeKalb is the seat of Northern Illinois Univ.