The first portion of the subway opened in 1904, and it was quickly expanded over the years. Before the system was consolidated, it was actually owned and operated by three different companies. The first, the IRT (Interborough Rapid Transit) system is now the numbered lines (1-7 and 9), or Division A. The lettered lines, or Division B, (A-G, J, L-N, Q-R, V-W, Z) was operated by either the BMT (Brooklyn-Manhattan Transit Company) or the IND (Independent Subway). You can still find marking in subways indicating how to get to the IND, IRT, etc. While the age of having three different companies operate the subway is over, it is interesting to see just how different each company built their stations, and how ruthlessly they tried to attract customers from the other companies.