MBTA Red Line begins service.

Operated jointly by the Boston Transportation Commission and the Boston Elevated Company, the subway line runs from the new Park Street Under Station to Harvard Square in Cambridge through a new tunnel under Beacon Hill and over the Longfellow Bridge. Construction began on August 12, 1909. The line is extended, via the new Dorchester Tunnel, to Washington Street in 1915,* South Station in 1916,* Broadway in 1917,* Ashmont in 1928,* to Quincy Center on September 1, 1971, to Braintree on March 22, 1980, and to Alewife in Cambridge on March 30, 1985.