In 1939, MA 28 entered the Boston area on Randolph St. It headed west onto Morton St to Jamaicaway, where it was paired with US 1 up to Revere Beach Parkway. It then headed north on Fellsway, Fellsway West and Forest St. C28 went up Blue Hill Ave to Seaver St, then took Columbus Ave to Charles St, crossed the Charles on the Longfellow Bridge and ended at Memorial Drive.
Between 1956 and 1958, 28 moved slightly. It left Randolph Ave at Reedsdale Rd, follow that to Brook Rd and then took Blue Hill Ave to Morton St.
The next change came in 1971, when the ‘C’ routes were removed. 28 took over the entire length of C28. The route has remained the same (basically) since.