Railroad service played a major role in Marion's history for more than a century. The first railcar rolled into Marion on October 13, 1859, a wood-burning train of the Dubuque Southern Railway. In 1872, the Sabula, Ackley, & Dakota Railway joined the Dubuque Southern in Marion, and the S.A. & D. later became the more commonly known Milwaukee Road. During the 1880s, the railroad brought a major boom to Marion, especially in 1887 when the town was named a Division Point, leading to the addition of a roundhouse, a new depot, and many new businesses and residents. Marion remained a Division Point until 1918. Freight and passenger service through Marion changed how the town was built and populated, with transported lumber changing house construction and a steady flow of travelers encouraging hotels, restaurants, and other businesses near the rail line to serve an expanding railroad workforce. Originally built in 1888, the C.M. & St. Paul Depot stood on 6th Ave. between 11th and 12th Streets, and in 1938 an extension added more office space. The two-floor depot served as Marion's railroad hub until the 1970s, when it faced demolition, but Marion citizens raised money and support to move the original depot roof to Marion Square Park for reuse as a pavilion roof, preserving part of this history. In the 1940s, airlines began competing heavily with railroad companies, and Marion saw its last passenger train on May 2, 1971. After that, only a struggling freight service remained, and on March 1, 1980, the Milwaukee Road's last train left Marion.