MBTA Red Line's 100th anniversary
The state bought the Cambridge Tunnel from the Boston El in 1920 and eventually bought the company outright in 1947. The company was transformed into the Metropolitan Transit Authority that year and in 1964 it became known as the Massachusetts Bay Transportation Authority.
The interior of the remodeled MTA tunnel train is pictured between Harvard and Central Squares on its first trip in 1948. It featured upholstered chairs, fluorescent lights, and polka-dot curtains.