30-71192 O Gauge RailKing Christmas Box CarThe 40 steel box car so familiar to model railroaders was a product of the 1930s. Wood box cars, which were built into the World War I era, and early steel cars were largely non standardized, with details varying from railroad to railroad. The move toward standardization began with American Railway Association (ARA) designs of 1923 and 1932. It culminated in the 1937 AAR boxcar, which was adopted by railroads from coast to coast and built in the tens