Benjamin Densmore enlisted in the Third Minnesota Infantry as a private and travelled south, where the Third's commander surrendered to Confederates in Tennessee. Densmore then returned to Minnesota and fought with the Third in the U.S.-Dakota War, but was hit by a bullet in the back of the head. He survived and returned south to help organize "contraband," or freed black men, into service for the Union. Densmore was promoted to captain and mustered out in 1866. He moved back to Red Wing and established an iron works.