A native of New York City, James McNamara grew up in a working-class family. His father worked for the MTA as a motorman and was a member of the Transport Workers Union. Young McNamara attended Cooperstown Academy, in Cooperstown, New York, but was expelled from the Academy after organizing a student protest. McNamara worked at Yankee Stadium where he operated the turnstile to admit people into the stadium. He organized the vendors at the ball park into Local 153 of the Office, Professional Employees International Union, whereupon he was "promoted" and promptly fired. He graduated from James Monroe High School in the Bronx and then attended Brooklyn College and the City College of New York. His first position in the labor movement was as an unpaid organizer for Local 155 of the ILGWU. He subsequently went to work for the hatters union. His first experience as a $50 per week organizer led to his once again being fired while trying to organize a shop in Hoboken, New Jersey. Moving across the river, he took up new duties for the hatters union in New York City.

He later served in a variety of capacities for the International Ladies Garment Workers Union, including International Representative, Director of Research and Education, Director of Organization; Manager of Local 102, Novelty Hat Workers Union; Administrator of the Local 3 Health Benefit Fund; and Trustee of the Local 80 Health Benefit and Retirement Funds. His responsibilities included organizing and servicing new locals in sixteen states and Puerto Rico, negotiation of collective bargaining agreements, and the drafting and implementation of contracts. In 1966 McNamara left union work to begin his second career as a civil servant.

Mayor John Lindsay recruited McNamara to work in his new administration as the Director of Community Relations for Labor and Industry in the Human Resources Department. In March 1968 McNamara took up new duties as Special Assistant to the Commissioner of Model Cities in the Human Resources Department (MCDA/HRA). In this capacity, he represented the Mayor's office in negotiations with the building trades (unions and employers associations), community groups and city agencies in launching pilot projects in Model Cities areas. In July 1970, McNamara took on the position of Director of the Building Trades Training Department in New York City's Manpower and Career Development Agency, part of the Human Resources Administration (HRA, now the Department of Employment). He conceived and implemented Mayor's Executive Order #20, which required on-the-job training of minority workers in all city-assisted construction.

In October 1973 McNamara took up the position of Director of the Office of Contract Compliance, and Deputy Director of the Bureau of Labor Services, Office of the Mayor, New York City. Here he was instrumental in creating and expanding the new office of C.C./Construction, and in developing rules, regulations, and contract language for New York City's affirmative action programs. In March 1977 he became the Assistant Commissioner of the New York State Division of Human Rights. Here he supervised the implementation of the Governor's Executive Orders on Equal Opportunity and Affirmative Action, as well as serving as the Director of the Office of State Contract Compliance Programs (E.O.45) and Affirmative Action in State Agencies (E.O. 40). He supervised the administration of state contracts with the Recruitment and Training Program, Inc., for minority recruitment in the building trades.

From September 1981 to January 1983, McNamara served as the Director of the Mayor's Office of Construction Industry Relations. Reporting directly to the Mayor, he coordinated the City's activities in combating employment discrimination and extortion in the construction industry. In February 1983, he became a consultant to the New York State Commission of Investigation in connection with a study of the building trades and construction industry practices. He served as an expert witness in public hearings which were conducted as part of the investigation.

In October 1985 he was assigned to the New York State Organized Crime Task Force by the Mayor's Office and the Commissioner of Investigation to assist in an investigation of the New York building trades and construction industry. In April of 1990 he was assigned to the construction industry project of the New York City Commission of Human Rights and the New York City Office of Labor Services. The investigation focused on race and gender discrimination, and McNamara carried out research in preparation for the public hearings.

In March 1993 McNamara became a consultant to the District Attorney's Office, County of New York, in the Labor Racketeering Unit. Again, he performed research for investigations of labor racketeering in the construction industry. In 1992 James McNamara retired after a twenty-five year career. In addition to his official duties, McNamara has been active in numerous organizations. He serves on the boards of the Workers Defense League and the Association for Union Democracy. He also serves as the Research Director for the AUD. He is the Secretary and Member of the Board of Directors of the Sixth Avenue Credit Union, Past President of the Gouverneur Gardens Housing Cooperative, a former member and Treasurer of the Board of Directors, Lower Eastside Neighborhood Association, the former Vice Chairman of Local School Board #3 and the Chairman of the Site Selection and Construction Committee. McNamara has also worked as spokesman for the International Longshoremen Association.

He has served as an expert witness in numerous cases involving discrimination and corruption in the building trades and construction industry. He has been at the center of the major struggles for the last quarter century in New York City involving the effort to open up the building trades unions to minority workers and to women, along with the repeated efforts of government agencies to clean up corruption in the industry. His wife, Ann Cadmus McNamara, an attorney, was General Counsel, New York City Department of Employment.