He was the 14th and 16th mayor of Green Bay, Wisconsin, and served as treasurer of the relief organization for the victims of the 1871 Peshtigo fire.

After graduating, he attended Andover Theological Seminary, intent on following after his father into a church career; he was forced to abandon his studies in 1839 due to poor health.

During the 1850s, Green Bay was a stop on the Underground Railroad; it is recorded that on at least one occasion Kimball personally helped hide and secure passage for a family who had escaped from slavery, on their way to Canada.

While serving as mayor in 1871, the great Peshtigo fire struck northeast Wisconsin, burning more than a million acres and killing an estimated 1,500–2,500 people.

In addition to his service as mayor, Kimball also served as a member of the city council and the local school board, and was appointed postmaster of Green Bay from 1877 to 1884.

After a brief, sudden, illness, Alonzo Kimball died at age 91, on August 7, 1900, at the home of his son, Charles, in Green Bay.