Eastern Blvd then serves as the main drag through Essex and Middle River. In 1942, as part of the Defense Highways Act, part of Eastern was dualized and rerouted east of Essex. Until it was purchased by the state, Martin was the nation's largest private airfield. The old route became Old Eastern Ave MD 600, which it retained until 1970. At the same time, the new sections of Eastern, from the Back River bridge all the way to Carroll Island Rd, was changed from avenue to boulevard, to indicate a change in house numbering.
Similar arrangements exist for other Baltimore suburbs, but none involve a change of road name.
Eastern Ave Extended is a 2 lane road east from Carroll Island Rd east to the end of state maintenance in Chase, at the intersection with Graces Quarters Road and what used to be Ebenezer Road when it was a grade railroad crossing. This piece of Ebenezer between Eastern and the tracks was a part of the former MD 149. Here now MD 17 north of US 40. No longer assigned, entire route now part of MD 17. Created when MD 17 between US 40 and Alt US 40 was dropped from state maintenance.