In 1818, Congress passed the first of three major Revolutionary War pension acts. The act granted lifetime pensions to all men who had served as regular army soldiers in the Continental Line and who could demonstrate financial need. Prior to the passage of this act, pensions had been restricted to former soldiers who were no longer able to support themselves due to injuries sustained while in service. The second act, passed by Congress in 1820, required applicants to provide more concrete evidence of this financial need in the form of a certified inventory of his property and income. They also had to include an account of all members of the applicant's family, including their health and ability to contribute to household income. In 1832, the third act extended pension benefits to include soldiers who had served in the state troops or militia. Congress also passed a related act in 1836 granting pensions to the widows and orphans of Revolutionary War veterans.

Accomack County was named for the Accomac Indians, who lived on the Eastern Shore at the time of the first English settlement in Virginia. The word means “on-the-other-side-of-water place” or "across the water." It was one of the original eight shires, or counties, first enumerated in 1634 and spelled Accomac without the k. The county's name was changed to Northampton County in 1643. The present county was formed from Northampton about 1663. In October 1670, the General Assembly temporarily reunited Accomack and Northampton Counties as Northampton County. In November 1673, Accomack County was again separated from Northampton. In early records, the county’s name was spelled many ways. In 1940 the General Assembly adopted the present spelling, Accomack. The county gained a small part of the southern end of Smith’s Island from Somerset County, Maryland, in 1879, after the United States had approved boundary changes between Virginia and Maryland that had been agreed to in 1877. The county seat is Accomac.

Accomack County is one of Virginia's Lost Records Localities. A significant number of loose records from the 1700s suffered extreme water and pest damage. Volumes that record deeds, court orders, and wills exist.