MD 135 attained its present alignment through several projects in the mid to late 1950s, concurrent with MD 135's extension west over part of MD 38 and all of MD 41 to Oakland in 1956. The segment of MD 38 in Deer Park was bypassed by the newly extended state highway in 1956. The state highway between McCoole and Westernport was relocated, and Bloomington Hill Road was bypassed with a straighter highway featuring a grade-separated crossing of the railroad in Bloomington in 1956 and 1957. The present section of MD 135 between MD 38 and Swanton Road was built in 1955 and 1956; MD 135 was then removed through Swanton and partially replaced by MD 495. The segment between Swanton Road and Bloomington Hill Road was upgraded between 1953 and 1956. Finally, the portion of MD 135 between Deer Park and Oakland, including the bypass of Mountain Lake Park, was rebuilt between 1957 and 1959.