Chicago & North Western
Delaware, Lackawanna & Western
Lake Shore
Louisville & Nashville
Missouri Pacific
New York Central
Northern Pacific Pfd
Pacific Mail
St Paul
Union Pacific
Western Union

Pacific Mail was a Steamship company.
Western Union was a Telegraph company.
All the other constituents were Railways.

By tracking the constituents of the index, and later Transports and Industrials indices, it can be analysed with regard to Dow Theory. By tracking the changes through history, and their relevance to the economy at the time, eventually the current index can be evaluated in terms of the Dow Theory.