Complex sentence: WGXA began broadcasting on April 21,1982 as an ABC affiliate, the last of the "Big 3" network affiliate stations in Middle Georgia after CBS affiliate WMAZ-TV and NBC affiliate WCWB-TV (now WMGT-TV).
Split into simpler sentences: WGXA began broadcasting on April 21,1982 as an ABC affiliate. It was the last of the big three stations in Middle Georgia after CBS affiliate WMAZ-TV and NBC affiliate WCWB-TV (now WMGT-TV).