[9] During his mayoralty, he was a leader in the municipal annexation of unincorporated areas through a vote held in September 1949.
Other notable projects during his mayoralty included an expansion of the city's airport, the expansion of Legion Field by 20,00 seats, the creation of eleven parks for "negro" residents and seven new parks for white residents, and many other projects.
[10] In 1941, Green joined with mayors of nearby cities to call for residents to contribute to a drive aiming to raise $50,000 for the British War Relief Society.
[14] In 1941, the Alabama Softball Association's board of governors elected Green to serve as the organization's president.
[15] Cooper also served as president of the Alabama League of Municipalities during the final three years of his mayoralty.
[5] In 1947, Green and two other U.S. mayors were appointed by the U.S. secretary of state to study municipal issues in postwar Europe.
[1][5] Before he tendered his surprise resignation in order to enter the private sector, he had been widely speculated as a possible candidate for governor in 1954.
[1] Upon his resignation, Dan Cobb of The Birmingham News wrote, "Probably no man in Alabama is better known than Cooper Green.
[17] In March 1965, Governor George Wallace appointed Green to serve as the president of the Jefferson County Commission.
[19] Among other actions, Green advocated for Mercy Hospital, and oversaw an expansion of the county's Juvenile Court.