[3] Kimball served as architectural adviser to commissions responsible for erection of the Missouri and Nebraska state capitols, the Kansas City Liberty Memorial, and the Indiana War Memorial in Indianapolis, and was a member of the national council of fine arts established by U.S. President Theodore Roosevelt to evaluate all plans for public buildings, monuments, and statutes.

In 1891, Kimball formed an architectural firm with MIT instructor C. Howard Walker and architect Herbert Best.

Kimball began attracting many high-profile projects in Omaha, including St. Philomena's Cathedral and the Burlington Train Station.

[12] The 1898 Trans Mississippi and International Exposition was a World's Fair-like event in Omaha that required the construction of many buildings.

Kimball won commissions for major new projects, such as St. Cecilia Cathedral and the Fontenelle Hotel in Omaha, and the Electricity Building at the 1904 World's Fair in St.

[13] By 1918, he had gained tremendous stature among his peers and was elected national president of the American Institute of Architects, an office he held until 1920.

Kimball was involved in many architecture-related activities, including supervision of the 1920 design contest that selected Bertram Goodhue as architect of the Nebraska State Capitol.

Among other commissions, the firm designed the Second Church of Christ Scientist (Minneapolis, 1930) and with George B. Prinz were associate architects on the Federal Office Building (Omaha, 1933).

Upon his death, partner William L. Steele remarked that Kimball "did not...as the majority of his contemporaries did, absorb a repertoire of French tricks and come home.

[18] Kimball also designed the original Omaha World-Herald building, the First National Bank in Grand Island and the Hastings, Nebraska Railroad Station.