THE NMRA....was formed in Milwaukee in the United States in 1935 by just on 100 modellers, mainly O Scalers, who believed standards should be introduced to allow interchange of their equipment and to provide some uniformity in the products of the various cottage industry manufacturers of that time. There were no standard voltages, both DC and AC power was in use and there were no coupler height or clearance standards. Everybody was going their own way and something had to be done.

Over the years the NMRA has grown to around 25,000 members in 42 countries with 90% being residents of the United States and Canada. The NMRA continues to be in the forefront of setting standards and recommended practices for the model railroad hobby and it works closely with the model railroad publishing, manufacturing and marketing industries to ensure the modeller's interests continue to be best served.