From the WBAI website.
WBAI began as WABF in 1941 and moved to 99.5 FM in 1948. The station took a respite from broadcasting in 1953, and came back on the air as part of World Broadcast Associates, Inc (WBAI) in 1955.
The Pacifica Foundation was launched by pacifist Lew Hill in 1949 with the first ever listener funded radio station – KPFA, Berkeley. The Pacifica Mission called for radio that would foster understanding amongst nations and individuals, encourage creativity, and promote innovative, uncensored distribution of news.
On January 10, 1960, WBAI joined Pacifica when philanthropist Louis Schweitzer gave the station to the network. Pacifica now has 5 radio stations (the other four are in Berkeley, Los Angeles, Houston, and Washington, DC) and more than 50 affiliate stations across the U.S.