Mooney began his career as an educator teaching junior high school government in Cincinnati, Ohio, and quickly became active in the American Federation of Teachers local affiliate there.
Mooney was elected President of the Cincinnati Federation of Teachers, Local 1520 of the AFT, AFL-CIO, at age 24, was re-elected many times, serving from 1979 to 2000.
As chair of the AFT's Professional Issues Committee, Mooney remained focused on the classroom teacher's perspective and voice.
He believed the union must lead reform, collaborate with the administration whenever possible, engage the adversaries of public education, but always put forward a strong teachers' voice, with bold ideas.
[1] Mooney was married to Debbie Schneider, who lives in Washington and works for the Service Employees International Union as the director of Global Organizing Partnerships.