For a century, it has served the Midwest with one of the station’s biggest AM radio signals. From the 1960s through the mid-1980s, it was one of the world’s most-listened-to Top 40 radio stations.

Cumulus Media Chicago’s WLS-AM 890 marked its 100th anniversary this month. Launched on April 12, 1924, as “The Sears-Roebuck Station,” WLS-AM has transitioned from a farming station to a rock ‘n’ ...