Keeping large bodies of militia in the field required an elaborate system of support based on the purchase of goods and services from civilians, in addition to the usual pay and allowances to officers and soldiers. The result was the creation of a large number of records concerning the state's disbursements to both soldiers and civilians. Many claims for payment went unsatisfied until 1821. Locality military and pension records consist largely of pay and muster rolls, accounts and vouchers concerning supplies, claims for reimbursement for services rendered, and military pension applications. Pension applications summarize the applicant's service record and may include medical evaluations; information about income and property; and, in the case of widows, the date and place of marriages.

During the Revolutionary War, commissioners were appointed in each county to impress supplies and non-military services (such as driving cattle or wagons) for the war effort. Officials provided certificates or receipts so that individual suppliers could be reimbursed by the state government. Beginning in 1782, claims for reimbursement could be submitted to county courts. These "publick claims," known as court booklets and lists, exist for almost all Virginia counties. Between 1777 and 1785, the Virginia General Assembly passed several laws authorizing pensions for disabled soldiers and for widows of soldiers who died while on active duty.

Throughout the Civil War, the principal responsibility for Virginia's indigent soldiers' families lay with the locality. The Virginia State Convention in 1861 gave the responsibility entirely to counties and incorporated towns and authorized whatever actions had already been taken. Acts of Assembly in 1862 and 1863 expanded the localities' powers to provide for their needy, and in 1863 some minimal state assistance was added in. The Virginia General Assembly passed several Confederate pension acts beginning in 1888. The initial act provided pensions to Confederate soldiers, sailors, and marines disabled in action and to the widows of those killed in action. A 1900 act broadened the coverage to include veterans disabled by "infirmities of age" and widows whose husbands died after the war. African Americans who had served "faithfully" as servants, cooks, laborers, hostlers, or teamsters for the Confederate army were eligible for pensions beginning in 1924. District of Columbia residents became eligible in 1926; previously, all pension applicants were required to be residents of Virginia.

Essex County was named probably for the English county or perhaps for Algernon Capell, second earl of Essex. It was formed from Old Rappahannock County in 1692. The county seat is Tappahannock.