Amherst County was formed from Albemarle County in 1761. Islands in the Fluvanna (now the James) River were added in 1770. The county is named for Major General Jeffery Amherst, British commander in North America during the later part of the French and Indian War and governor of Virginia from 1759-1768.

The Board of Supervisors is the basic governing body of the county. County laws--called ordinances--may also be passed by this board. This form of government came into existence with the state constitution of 1869 when the counties were divided into a minimum of three townships each, with a popularly elected supervisor from each township. When the township system was abolished in 1875, the counties were divided into magisterial districts. The Board of Supervisors are the current elected representatives of these districts and meet in regular monthly public sessions.

Until 1869 the county court controlled construction, alteration of, and maintenance of roads. The state constitution of 1869 created overseers of the roads and road boards which fell under the jurisdiction of the county's board of supervisors. By 1908 (according to an on line history of roads prepared by Virginia's Department of Transportation), the need for better roads in Virginia had reached the point that the legislature made its first appropriation for construction purposes under the new state program. Money provided by the state was to be matched equally by the counties paying for road improvements. During this period, state law directed the counties to levy a road tax of up to 40 cents for each $100 in value on real estate and personal property, with the revenue to cover the counties' share of improvements and to buy road equipment. In addition, the counties were authorized to issue bonds.