What is today's Franklin Branch was a portion of the Midland Line of the New Haven's Midland Division, the New Haven's secondary route between Boston and New York; the MBTA's Dorchester Branch and the abandoned segments from Franklin to Willimantic, Connecticut via Blackstone were the remaining components of the Midland Line. In 1910, the passenger route on the Midland Line was a regional inter-city train that continued to New York via the Highland Line segment of the Highland Division between Willimantic and Waterbury, Connecticut, then continuing down the Housatonic Railroad to the New Haven Line. Service was eventually shortened to Waterbury in 1937.