Isaac Kalbach opened the first lumber company in Oskaloosa in 1864. The company began operating in a stage coach barn where the current Oskaloosa City Hall sits. In 1867, Kalbach built this office building along with lumber sheds. It served as the company headquarters until 1902 when the company acquired more land and built a new warehouse and office. The company used the original office building as storage until it was moved by MCHS in late 1986.
Kalbach Lumber was a family-operated business for five generations. In addition to purchasing lumber and building materials, customers could also pay their mortgage, rent, or utility bills. It closed in 1998 and then became Kalbach’s Ace Hardware.