General Arlington History

During the Civil War, 1861 to around 1865, Arlington was occupied by Union soldiers. These soldiers were trying to protect the nation's capital, however, most of the crops in Arlington were destroyed and the trees were cut down for the use of building materials. During the time period before 1870 the territory that is now Arlington County, was a part of Alexandria County. It was the area outside of the City of Alexandria, and was a rural farming community. The U.S. census in 1860 calculated that in the "country part"(Arlington) of Alexandria there were 1,486 residents, 251 of which were slave holders, and there were a total of 982 slaves in the area. Even though the area is so close to Washington D.C., at the time it was not influenced much by the rapid growth of the city just across the Potomac River.
Years Later in 1920, Arlington County was made separate from the City of Alexandria. It was named after Robert E. Lee's, Arlington Estate. In the years after the civil war into the 20th century Arlington started to become less of a rural town. There was a trolley put in that ran through the entire county, and the invention of the automobile made it easier for the residents to travel throughout the county. The Depression and World War II increased the need for government workers in D.C., which in turn created a high demand for housing in Arlington County. This demand helped Arlington transition from mostly farmland to a more suburban area. This is when communities such as Colonial Village, Buckingham, and Fairlington were created. The the Pentagon opened, it only increased the demands in Arlington, and started the process of creating public libraries and transportation.
Arlington steadily started to become more urbanized post World War II. This led to the redevelopment of areas such as Rosslyn and Crystal city. The metro system was put into place between 1977 and 1986. All of this change and urbanization continued to change Arlington, not only physically but also the areas population. The county increasingly became more integrated, and in 1956 became involved in the movement to integrate public schools. This led to what is now an ethnically diverse county with many urban villages throughout its boundaries.

http://www.arlingtonhistoricalsociety.org/
http://library.arlington.us/departments/libaries/history/librarieshistorylocalhistory.asp