Radio station WJMO began broadcasting on 1 June 1947 at frequency 1540. WENTWORTH J. MARSHALL was the station owner and David M. Baylor its general manager. The station's specialty was recorded music, and one of its personalities was GENE CARROLL.
In 1952 the station was sold to Maryland-based United Broadcasting. Six years later station WSRS/1490 of CLEVELAND HTS. was purchased, and WJMO took over that station's frequency and offices. During the 1950s, WJMO had moved to a black-oriented format. In 1970 a dispute over the lack of blacks (see AFRICAN AMERICANS) in key positions and regarding working conditions attracted the involvement of a number of groups, including the Southern Christian Leadership Conference. As a result Ken Hawkins was appointed general manager that year, the first African American to hold that position at a Cleveland radio station. In Jan. 1990 station WRQC-FM/92.3 was acquired by United Broadcasting and renamed WJMO-FM.
In 1992 the sale of WJMO-FM and AM to Zapis Communications (Xenophon Zapis), Lynn Tolliver, and Bobby (Otis) Rush through their Zebra Communications was announced. Tolliver and Rush, both African Americans, worked at WZAK. From 1992 to 1994, the sale was contested by the Southern Christian Leadership Conference. When the sale was approved by the FCC in 1993, WJMO became the first radio station with significant African American ownership in the Cleveland area. As a result of the legal battles the SCLC gained significant control of the less profitable WJMO-AM. In 1994 WJMO-FM was renamed WZJM-FM/92.3.