In 1873, a twenty-nine-year-old Kimball travelled to London to meet with the architect William Burgess and Trinity’s President Abner Jackson. He became close with both men and their project, and was soon a crucial member of the architectural team. In a report to Trinity’s trustees Burgess praised him, saying, “I do not think you could obtain another gentleman who possessed so much knowledge of the work itself and so much zeal for its future execution.” During his time in England, Kimball was exposed to the Gothic architecture that would play such a notable role in his later works. Kimball returned to Hartford with the Burgess plans for the college, but soon after his return President Jackson died, and the new administration decided against the costly initial blueprint. With the assistance of Frederick Law Olmstead, Kimball worked to reduce the academic and residential buildings to a single long edifice, consisting of Jarvis, Northam, and Seabury halls.
After the completion of Trinity’s New Campus Kimball began specializing in theatre buildings, taking several jobs in New York City. He spent several years working independently, collaborating when necessary while focusing on the development of his own distinctive style. He gained renown for his use of terracotta ornamentation (which was used on the roofs of Seabury, Jarvis, and Northam). In 1892 he became co-head of the firm Kimball and Thompson, where he worked on what is now called The Church for all Nations. It was one of his most renowned works, done in the late Victorian Gothic Style. After the death of his business partner in 1898, Kimball continued independent work until his own death in 1919.