Talks on expanding were held in 1950 and 1951 because of increasing enrollments at some schools, but action was not taken until 1952 when Anthony Wayne left the Maumee Valley League to join the GNC gradually, starting with the spring of 1953 in baseball.

Sylvania was forced to cancel its winter and spring sports during the 1957-58 school year after a levy attempt failed in the fall of 1957.

Source:[2] Talks had begun in 1956 to expand the GNC with Bowling Green, Fostoria, Swanton, Oak Harbor, Genoa, Lake, Port Clinton, Toledo Rogers and Holland being considered.

At this time, the GLL consisted of Bedford, Bowling Green, Clay, Fostoria, Port Clinton, and Sylvania.

Port Clinton left at the start of the 1980-81 school year for the Sandusky Bay Conference and was replaced by Lima Shawnee, which competed in the GLL only in 1980-81 and 1981-82.

The GBC was created in fall of 2003 with Findlay, Fremont Ross, Lima Senior, Marion Harding, Napoleon, and Sandusky as the inaugural members, after the GLL ceased to exist.

On May 24, 2010, representatives from Findlay and Lima Senior high schools met with the non-TPS members of the Toledo City League to discuss possibly forming a new conference no sooner than 2011.

This came after Toledo Public considered cutting junior high, freshmen, and less popular sports from their budget in order to ease their $39 million deficit.