He was educated in the Boston public schools, and as a young man worked in the office of architect Edmund M. Wheelwright.

In 1898, Sullivan resigned to form a partnership with architects Charles Donagh Maginnis and Timothy Walsh.

His work included parish churches and schools as well as larger projects like Harkins Hall, the main building of Providence College.

[1] Sullivan frequently utilized the services of woodcarver Johannes Kirchmayer of Irving & Casson in his designs.

[9] Kathrine Sullivan was involved in anti-suffragist activism in Massachusetts[10] and later was a trustee of Westborough State Hospital.

It was built using a structural system of specially designed terra cotta blocks which offered protection from fire as well as insulation.