MD 198 was constructed from US 1 in Laurel west toward Burtonsville in the early 1920s and completed in the late 1920s. Another section was built in Spencerville in the late 1920s; the two segments were connected in the mid-1950s. The Laurel–Fort Meade road was built as MD 602 for military access purposes in the mid-1940s, replacing the original highway between the two locations, MD 216. MD 198 was relocated through Laurel and extended east along MD 602 to Fort Meade in the early 1960s. The first divided highway portion of the highway was part of a relocation at the Interstate 95 (I-95) interchange in the early 1970s. The divided highway was extended west to Burtonsville in the mid-1980s and through Maryland City in the late 1980s. MD 198's eastern end was extended to MD 32 in the early 1990s and then moved again for its interchange with that highway in the early 2000s. The Maryland State Highway Administration (MDSHA) plans to expand the remaining two-lane portions of MD 198 to a divided highway.