Arlington County is a county in the Commonwealth of Virginia. The land that became Arlington was originally donated by Virginia to the United States government to form part of the new federal capital district. On February 27, 1801, the United States Congress organized the area as a subdivision of the District of Columbia named Alexandria County. In 1846, Congress returned the land donated by Virginia due to issues involving Congressional representation and the abolition of slavery. The General Assembly of Virginia changed the county's name to Arlington in 1920 to avoid confusion with the adjacent City of Alexandria.
The county is situated in Northern Virginia on the south bank of the Potomac River directly across from Washington, D.C. Arlington is also bordered by Fairfax County and the City of Falls Church to the southwest, and the City of Alexandria to the southeast. With a land area of , Arlington is the geographically smallest self-governing county in the United States and has no other incorporated towns within its borders. Given these unique characteristics, for statistical purposes the county is included as a municipality within the Washington Metropolitan Area by the United States Census Bureau. As of 2010, Arlington County had a population of 207,627 residents. It would be the fourth-largest city in the state if it were incorporated as such.
Given the county's proximity to Washington, D.C., Arlington is headquarters to many departments and agencies of the federal government of the United States, including the Pentagon, the Department of Defense, the United States Drug Enforcement Administration, the Defense Intelligence Agency and the Defense Advanced Research Projects Agency (DARPA). The many federal agencies, government contractors, and service industries contribute to Arlington's stable economy, which has made it one of the highest-income counties in the United States. Arlington is also the location of national memorials and museums, including Arlington National Cemetery, the Pentagon Memorial, the Marine Corps War Memorial, and the United States Air Force Memorial.
The area that now constitutes Arlington County was originally part of Fairfax County in the Colony of Virginia. Land grants from the British monarch were awarded to prominent Englishmen in exchange for political favors and efforts at development. One of the grantees was Thomas Fairfax, 6th Lord Fairfax of Cameron whose lends his name to both Fairfax County and the City of Fairfax. The name Arlington comes from Henry Bennet, 1st Earl of Arlington whose name had been applied to a plantation along the Potomac River. George Washington Parke Custis, grandson of First Lady Martha Washington, acquired this land in 1802. The estate was eventually passed down to Mary Anna Custis Lee, wife of General Robert E. Lee. The property later became Arlington National Cemetery during the American Civil War, and now lends its name to present-day Arlington County.
The area that now contains Arlington County was ceded to the new United States federal government by the Commonwealth of Virginia. With the passage of the Residence Act in 1790, Congress approved a new permanent capital to be located on the Potomac River, the exact area to be selected by President George Washington. The Residence Act originally only allowed the President to select a location within Maryland as far east as what is now the Anacostia River. However, President Washington shifted the federal territory's borders to the southeast in order to include the pre-existing city of Alexandria at the District's southern tip. In 1791, Congress amended the Residence Act to approve the new site, including the territory ceded by Virginia. However, this amendment to the Residence Act specifically prohibited the "erection of the public buildings otherwise than on the Maryland side of the River Potomac." As permitted by the U.S. Constitution, the initial shape of the federal district was a square, measuring on each side, totaling . During 1791–92, Andrew Ellicott and several assistants placed boundary stones at every mile point. Fourteen of these markers were in Virginia and many of the stones are still standing.
When Congress arrived in the new capital, they passed the Organic Act of 1801 to officially organize the District of Columbia and placed the entire federal territory, including the cities of Washington, Georgetown, and Alexandria, under the exclusive control of Congress. Further, the unincorporated territory within the District was organized into two counties: the County of Washington to the east of the Potomac and the County of Alexandria to the west. This Act formally established the borders of the area that would eventually become Arlington but the citizens located in the District were no longer considered residents of Maryland or Virginia, thus ending their representation in Congress.
Residents of Alexandria County had expected the federal capital's location to result in land sales and the growth of commerce. Instead the county found itself struggling to compete with the Chesapeake and Ohio Canal at the port of Georgetown, which was farther inland and on the northern side of the Potomac River next to the City of Washington. Members of Congress from other areas of Virginia also used their power to prohibit funding for projects, such as the Alexandria Canal, which would have increased competition with their home districts. In addition, Congress had prohibited the federal government from establishing any offices in Alexandria, which made the county less important to the functioning of the national government.
Alexandria had also been a major market in the American slave trade, and rumors circulated that abolitionists in Congress were attempting to end slavery in the District; such an action would have further depressed Alexandria's slavery-based economy. At the same time, an active abolitionist movement arose in Virginia that created a division on the question of slavery in the Virginia General Assembly. Pro-slavery Virginians recognized that if Alexandria were returned to the Commonwealth, it could provide two new representatives who favored slavery in the state legislature. During the American Civil War, this division led to the formation of the state of West Virginia, which comprised the 55 counties in the northwest that favored abolitionism.
Largely as a result of the economic neglect by Congress, divisions over slavery, and the lack of voting rights for the residents of the District, a movement grew to return Alexandria to Virginia from the District of Columbia. From 1840 to 1846, Alexandrians petitioned Congress and the Virginia legislature to approve this transfer known as retrocession. On February 3, 1846, the Virginia General Assembly agreed to accept the retrocession of Alexandria if Congress approved. Following additional lobbying by Alexandrians, Congress passed legislation on July 9, 1846, to return all the District's territory south of the Potomac River back to the Commonwealth of Virginia, pursuant to a referendum; President James K. Polk signed the legislation the next day. A referendum on retrocession was held on September 1–2, 1846. The residents of the City of Alexandria voted in favor of the retrocession, 734 to 116; however, the residents of Alexandria County voted against retrocession 106 to 29. Despite the objections of those living in Alexandria County, President Polk certified the referendum and issued a proclamation of transfer on September 7, 1846. However, the Virginia legislature did not immediately accept the retrocession offer. Virginia legislators were concerned that the people of Alexandria County had not been properly included in the retrocession proceedings. After months of debate, the Virginia General Assembly voted to formally accept the retrocession legislation on March 13, 1847. In 1852, the Virginia legislature voted to incorporate a portion of Alexandria County to make the City of Alexandria, which until then had been only been considered politically as a town.
During the American Civil War, Virginia seceded from the Union as a result of a statewide referendum held on May 23, 1861; the voters from Alexandria County approved secession by a vote of 958–48. This vote indicates the degree to which its only town, Alexandria, was pro-secession and pro-Confederate. The Union loyalists who lived in rural areas outside the town of Alexandria, rejected secession. Although Virginia was part of the Confederacy, its control did not extend all the way through Northern Virginia. In 1862, the United States Congress passed a law that provided that those districts in which the "insurrection" persisted were to pay their real estate taxes in person.
In 1864, during the war, the federal government confiscated the Abingdon estate, which was located on and near the present Ronald Reagan Washington National Airport, when its owner failed to pay the estate's property tax in person because he was serving in the Confederate Army. The government then sold the property at auction, whereupon the purchaser leased the property to a third party.
After the war ended in 1865, the Abingdon estate's heir, Alexander Hunter, started a legal action to recover the property. James A. Garfield, a Republican member of the United States House of Representatives who had been a Brigadier General in the Union Army during the Civil War and who later became the 20th President of the United States, was an attorney on Hunter's legal team. In 1870, the Supreme Court of the United States, in a precedential ruling, found that the government had illegally confiscated the property and ordered that it be returned to Hunter.
The property containing the home of Confederate General Robert E. Lee's family at and around Arlington House was subjected to an appraisal of $26,810, on which a tax of $92.07 was assessed. However, Lee's wife, Mary Anna Custis Lee, the owner of the property, did not pay this tax in person. As a result of the 1862 law, the Federal government confiscated the property and made it into a military cemetery.
After the war ended and after the death of his parents, George Washington Custis Lee, the Lees' eldest son, initiated a legal action in an attempt to recover the property. In December 1882, the U.S. Supreme Court found that the federal government had illegally confiscated the property without due process and returned the property to Custis Lee while citing the Court's earlier ruling in the Hunter case. In 1883, the U.S. Congress purchased the property from Lee for $150,000, whereupon the property became a military reservation and eventually Arlington National Cemetery. Although Arlington House is within the National Cemetery, the National Park Service presently administers the House and its grounds as a memorial to Robert E. Lee.
Confederate incursions from Falls Church, Minor's Hill and Upton's Hill—-then securely in Confederate hands—-occurred as far east as the present-day area of Ballston. On August 17, 1861 an armed force of 600 Confederate soldiers engaged the 23rd New York Infantry near that crossroads, killing one. Another large incursion on August 27 involved between 600 and 800 Confederate soldiers, which clashed with Union soldiers at Ball’s Crossroads, Hall’s Hill and along the modern-day border between the City of Falls Church and Arlington. A number of soldiers on both sides were killed. However, the territory in present-day Arlington was never successfully captured by Confederate forces.
In 1896, an electric trolley line was built from Washington through Ballston, which led to growth in the county.
In 1920, the Virginia legislature renamed the area Arlington County to avoid confusion with the City of Alexandria which had become an independent city in 1870 under the new Virginia Constitution adopted after the Civil War.
In the 1930s, Hoover Field was established on the present site of the Pentagon; in that decade, Buckingham, Colonial Heights, and other apartment communities also opened. World War II brought a boom to the county, but one that could not be met by new construction due to rationing imposed by the war effort.
In October 1942, not a single rental unit was available in the county. The Henry G. Shirley Highway (now Interstate 395) was constructed during World War II, along with adjacent developments such as Shirlington, Fairlington, and Parkfairfax.
On September 11, 2001, five al-Qaeda hijackers deliberately crashed American Airlines Flight 77 into The Pentagon killing 125 Pentagon personnel and all 64 people on board, as part of the September 11 attacks.