The four companies continuing on to Wisconsin in August 1864 were ordered to the District of Minnesota. Their muster out in July 1865 was canceled and in October, they were ordered to build and garrison Fort Fletcher, Kansas, and man two outposts at Monument Station and Ponds Creek Station, also in Kansas, to protect the new Butterfield Overland Despatch stagecoach route. Companies A, F, G, and I of the 1st U.S.V.I. mustered out at Fort Leavenworth on May 22, 1866, after 25 months of active service, the longest service of any of the "galvanized Yankees."