James Chaffee Loomis graduated from Yale College and was admitted to the bar of Fairfield County. He served in various public roles, including in the Connecticut Senate, Connecticut House of Representatives, and as mayor of Bridgeport. Loomis also held leadership positions within the Congregational Society and the Fairfield County Bar Association. He made significant contributions to education, serving as a trustee for the Loomis Institute. Loomis's career included unsuccessful bids for governor, but he remained active in community and civic leadership.

James Chaffee Loomis's political career is marked by a unique blend of local leadership and educational advocacy, underpinned by a commitment to community institutions. His involvement in Bridgeport's civic life, from serving as mayor to leading the Board of Education, suggests a highly localized approach to governance. Notably, Loomis's dedication to the Loomis Institute, which he helped establish and fund, reveals an ideological focus on accessible education. Despite his unsuccessful bids for higher office, his consistent engagement in local governance and community organizations indicates a strategic, calculated approach to political influence.