WPLM-FM signed on June 25, 1961. In the station's first decades on the air, it had a big band format. This was abandoned in 1993 in favor of an adult contemporary format, branded "Variety 99.1". However, the station saw little success with this format, due to there being several other stations with a similar format within WPLM's coverage area, and as a result it switched to smooth jazz on June 25, 1995. Initially, programming was largely provided by SW Networks' Smooth FM service; (indeed, the station took the branding "Smooth FM 99.1") however, after Smooth FM closed on December 31, 1996, the station switched to a similar service from Jones Radio Networks and reimaged as "Jazzy 99.1". Two years later, this was discontinued in favor of the current "Easy 99.1" format. In the beginning, adult standards artists such as Frank Sinatra received a large amount of airplay, but the station has subsequently shifted to more of a contemporary format.[original research?].
From WPLM-FM's inception, its programming has been simulcast, in whole or in part, with its sister AM station, which signed on six years earlier; however, the AM station has gradually shifted some of its schedule to simulcasts of WADN/WBNW (1120) since 1997.
Notable past and present personnel include Audrey Constant, Chris Rogers, Ken Coleman, Ron Della Chiesa, Bill O'Connell, and Sean Casey.