[2][3] In 1861, Borchsenius entered the United States Army as adjutant of the Fifteenth Wisconsin Infantry, but owing to severe illness, he resigned before the cessation of hostilities.
Governor Ludington then appointed Borchsenius timber agent for the state to protect the railroad lands on the Chippewa and Red Cedar rivers.
While serving in this capacity, he became interested in northern Wisconsin and in 1877 he moved to Baldwin, to engage in the real estate and loan business.
In 1896, Borchsenius was elected a member of the Wisconsin State Assembly from St. Croix County[5] intending that this should be his last political office.
At the end of his legislative term, Borchsenius retired from active life and returned to Madison to live, building the home.
They had three children: William Carl, Dora H., and George Valdemar, who served as clerk of the United States court in Alaska.