Stevenson is an unincorporated community located in the Greenspring Valley in the northern section of Baltimore County, Maryland, United States. From 1830 until 1955, this community was served by the Greenspring Branch of the Northern Central Railway.Primarily a residential area, it is the site of the main campus of Stevenson University, which also has a campus in Owings Mills. It is also home to St. Timothy's School, an all-girls boarding and day high school. Fort Garrison was listed on the National Register of Historic Places in 1971.