Other stations along the line opened a year later in 1898 — Scollay, Adams, and Haymarket squares to North Station. These would become the basis for the eventual Green Line system. Trolley cars from 27 routes across Boston ran into the subway initially.
Officials then focused on building an elevated rail line, eventually known as the "EL," to outlying neighborhoods. It was seen as a cheaper and less troublesome project than digging tunnels.