A railroad water tower, servicing the 13 steam locomotives at the Mid-Continent Railway Museum, an outdoor, "living museum" and operating railroad that has (as of 2016) operated since 1963 in North Freedom, Wisconsin. Steam locomotives required large quantities of good-quality water to generate steam to power their trains. At the turn from the 19th to 20th centuries, most railroads used water towers trackside, often spaced along the track at stream crossings or in towns where trains stopped to pick of freight and passengers. Photo by Carol Highsmith.