md 180's crossing of the pennsylvania railroad was constructed in 1938. the highway was relocated through odenton using the new bridge in 1938 and 1939; the old road became md 677. md 175's bridge over the b&o railroad in jessup was completed in 1942. the highway was widened to a wide road with a concrete base and asphalt surface from jessup to the md 713 intersection in 1942. md 175 was also extended as a road through fort meade from md 713 to west of odenton between 1942 and 1944. by 1946, md 175 had been extended east over md 180 to millersville and west over md 531 to ellicott city; the portion of md 175 from fort meade to md 176 became md 713. md 175 was widened from from odenton to millersville starting in 1948. the highway was widened and resurfaced from odenton to the newly constructed baltimore–washington expressway interchange in 1954. md 175 was also widened with curve amelioration from us 1 to md 103 between 1954 and 1956.