A Legacy of Hard Work
John M. Brennan, Sr. emigrated from Ireland and started J.M. Brennan, Inc. at the height of the Great Depression. He served the Milwaukee community for more than 30 years. His son John M. Brennan, Jr. expanded the company’s capability and services over the next 35 years. By 1997, the next generation of Brennans was at the helm. Together, John and Matt Brennan have re-shaped the company as the leading mechanical contractor in Southeastern Wisconsin.
J.M. Brennan is proud to be family-owned since 1932.