Long Green Valley Historic District
The Long Green Valley Historic District is an approximately 6,066 acre rural agricultural area to the northeast of the city of Baltimore. The valley has a distinct physical unity created by gently rolling fields dotted with crossroads villages such as Glen Arm and Baldwin, and farm complexes. Its architecture covers the 18th, 19th, and early 20th centuries and is generally conservative with most of the major architectural styles of these periods evident. In some examples, more than one style is found in the same building because of renovations. The majority of the structures are domestic or farm related such as barns and utility buildings. Commercial structures stand in the village areas. The older structures are generally of stone or brick construction with frame dominating the mid 19th-century to present era. The houses vary in scale, design, and craftsmanship depending on the history of the structure. Approximately 125 individual buildings, complexes, and objects stand in the district with the majority contributing to the significance of the district. The major intrusions or non-obtrusive elements are industrial complexes around Glen Arm and groupings of post-1930s houses.
The significance of the Long Green Valley Historic District derives from the collection of 18th, 19th, and early 20th century buildings that are situated in a rural agricultural setting. The buildings, primarily houses and farm structures, embody the distinctive design characteristics of the major architectural styles popular in the United States from the Neoclassical of the 1700s to the Georgian Revival of the pre 1935 period. The buildings range from modest to elaborate in size and exhibit varying degrees of craftsmanship as well as a record of changes in construction techniques in Baltimore County. The buildings also are evidence in the productive agricultural nature of the valley since it was settled in the 1720s thus recording ways of life that have disappeared in other regions surrounding metropolitan Baltimore.