Chapters engage in broadly diversified activities. This is the great strength of the organization. Whether a member’s interest run to locomotives, signaling, operations, traction, models, research, preservation, restoration, collectibles, operating excursions or museums, writing and publishing or any other sub-division, there is a place for him or her and a contagious conduit for sharing enthusiasm.

In 1935, a handful of rail enthusiasts organized the National Railway Historical Society. As of 2016 the Society has 11,500 members and about 150 Chapters spread throughout the United States, Canada and Great Britain. It is now, by far, the United States' largest rail enthusiast organization. Membership is available regardless of race, religion, gender or national origin.