Great Northern Railway automobile box cars 43940 and 43948 were part of a series of one hundred fifty-foot wood single-sheath automobile box cars built by Great Northern Railway shops in St. Cloud, Minnesota, in June 1929, using Pullman-Standard frames. Designed to ship automobiles more securely than flatcars, they had twelve-foot-wide side door openings covered by two six-foot doors. They were originally built with wood doors, later changed to No. 50 Youngstown corrugated steel doors sometime before 1948. The full steel end doors on the A end, used for loading automobiles, were permanently closed between 1948 and 1955. In September 1963, Great Northern sold both cars to Longview Fibre Company for in-plant service moving corrugated paper materials at its Longview, Washington, facility, where GN 43940 became LFCO 367 and GN 43948 became LFCO 368. Longview Fibre donated both cars in 1984. Automobile box cars had wider side doors and end doors that gave them more loading flexibility than typical box cars, and many were loaded by hand, with workers pushing cars into place using floor jacks, dollies, and physical labor. Modern vehicle shipments typically use eighty- to ninety-foot flat cars fitted with auto racks, but the end-door concept remained an important part of loading and unloading design.