the number has changed over time, but Virginia has 95 counties now
Source: Virginia Department of Education, History and Social Science Standards of Learning (p.8)
There are 95 counties now existing in Virginia. The General Assembly has created subordinate county and city jurisdictions for nearly 400 years, and other counties have been dissolved, converted into cities, or lost to the Northwest Territory, Pennsylvania, Kentucky, and West Virginia. Several of the remaining 95 counties once had different names, and every remaining county has had its boundaries altered at one time or another.
Colony-wide government came first, starting with governance at Jamestown by a private joint-stock company. The Virginia Company initiated the Virginia legislature in 1619. The General Assembly established four "incorporations," and starting in 1634 created the counties.1
Forming new units of government with county courts helped the legislators offload to others some of the responsibilities/workload for handling land ownership changes, processing wills, and dealing with minor crimes. Similarly, creating parishes with vestry for Anglican churches helped offload the burden of providing social services for the destitute, assigning responsibility for illegitimate children, etc.
After 1634, each county was authorized to elect two memmbers to the General Assembly. Those members sat in the House of Burgesses, once it began to meet as a separate body in 1643. The process mimicked how the 40 counties in England sent two members each to the House of Commons.
Up to the American Revolution, the expansion of political authority roughly matched the migration of colonists inland:2
The counties did not unite to create Virginia; the state was not created by a vote of independent counties. Instead, the legislature of Virginia created the counties from the top down.
That is a key distinction between the formation of Virginia vs. formation of the Federal government. The US Congress and then an entire structure of Federal government were created from the bottom up. The first 13 states coordinated with each other "in Congress assembled" to unite into one nation.
The only authorities held by local jurisdictions were granted by the legislature. Local governments lack power to make decisions as challenging as land use planning, or as simple as hiring dogcatchers, unless the jurisdiction can identify a specific grant of authority from the General Assembly. Virginia courts interpret the grant of authority according to the Dillon Rule.
Three counties (Chesterfield, James City, and Roanoke) have specific charters from the General Assembly that spell out specific authorities. The rest are empowered to exercise governmental authority based on Title 15.2 of the Code of Virginia.3
click on a county to get more information
Source: Ray Sterner, ">Color Landform Atlas of the United States
during the Civil War, historic legal records were destroyed at many Virginia courthouses, including the one in Fairfax County
Source: National Archives, Fairfax Court House, Virginia, ca. 1860 - ca. 1865
Virginia had 95 counties and 38 cities, after the City of Bedford shifted to town status in 2013
Source: US Geological Survey (USGS) National Atlas, County Map