The T may sometimes seem like a slowly crumbling artifact, what with the mounting tales of derailments, fires, and delays. The system’s current state, however, is but a small part of a long story—one that, believe it or not, is really about innovation and being first. Before the T: Horsepower Boston lays claim to having the first subway system in the Western Hemisphere. Even prior to that, though, the city was on the cutting edge.