Henry C. Koch was born around 1841 in Hanover in present-day Germany to Albert and Sophia Koch. He eventually immigrated to America and settled in Milwaukee, Wisconsin. He enlisted in the Union army on August 18, 1862, and he mustered in as a private in Company B of the 24th Wisconsin Infantry. The regiment took part in the Battle of Perryville, the Battle of Stones River, and the Battle of Chickamauga. He eventually became a draftsman on General Philip Sheridan’s staff, and Sheridan praised his maps for their “accuracy of detail and beauty of finish.” He mustered out on May 20, 1865.
He returned to Milwaukee after the war, and he earned a living as an architect. By 1870, he owned $6,000 of real estate and $200 of personal property. He married Johanna Knab on June 1, 1869, and they had at least six children: Almand, born around 1870; Ella, born around 1873; Heinrich, born around 1879; Johanna, born around 1881; George, born around 1891; and Raymond, born around 1895. He became a prominent architecture in Milwaukee. He worked in the Richardsonian Romanesque style, taking inspiration from medieval architecture. His signature work was the 1895 Milwaukee City Hall. He died in Milwaukee on May 19, 1910.