A baseball player in high school in Chicago at Lane Tech, he played minor-league professional baseball briefly for the Green Bay Bluejays before becoming a Wisconsin sports broadcaster.
Gillespie was partnered with Blaine Walsh on WTMJ Radio and known for his dramatic, extroverted style of play-by-play, including exclaiming "...and the pass iiiizzCAUGHT!" during a successful football pass completion (conversely, a failed pass attempt met with "...and the pass iiiizz INNcomplete!"), and his use of the phrase "Holy cow!" during moments of great excitement (an on-air catchphrase he shared with fellow baseball announcers Halsey Hall, Harry Caray and Phil Rizzuto).
Earl's son John Sr., and grandson John Jr. also were Wisconsin sportscasters, with the younger John Gillespie leaving WBAY-TV in Green Bay in late July 2010.
Play-by-play highlights
On September 23, 1957, Gillespie described the Braves' capture of the National League pennant this way:
"The pitch to Henry Aaron. A swing and a drive back into center field! Going back towards the wall! It's back at that fence....and is it gone or not? It's a home run! The Braves are the champions of the National League! Henry Aaron has just hit his forty-third home run of the year!"
On October 10, 1957, Gillespie's description of the Braves' World Series win:
"The outfield around to the left. McDougald is on at third, Coleman is at second. Tommy Byrne the base runner at first. Hank Aaron is pulled around in left-center field. A breeze is blowing across from left to right. Burdette's pitch. Swung on, lined, grabbed by Mathews who steps on third--and the World Series is over and the Milwaukee Braves are the new world champions of baseball!"