Chancery Causes are cases of equity. According to Black's Law Dictionary they are "administered according to fairness as contrasted with the strictly formulated rules of common law." A judge, not a jury, determines the outcome of the case; however, the judge is basing the decision on findings compiled and documented by Commissioners. Chancery causes are useful when researching local history, genealogical information, and land or estate divisions. They are a valuable source of local, state, social, and legal history and serve as a primary source for understanding a locality's history. Chancery causes document the lived experiences of free and enslaved individuals; women; children; people living with physical disabilities or mental health struggles; people living in poverty; defunct institutions and corporate entities; or those that may not have otherwise left traditional written histories.

Tazewell County was originally named Alexandria County. It was formed from a portion of Fairfax County that Virginia in 1789 ceded to the federal government for use as the site of a new national capital. In 1801 the area officially became part of the District of Columbia, although Congress named it Alexandria County. By an act of 9 July 1846, Congress returned the county to Virginia, and the General Assembly extended the commonwealth's jurisdiction over the region effective 20 March 1847. By an act of assembly passed 16 March 1920, the county's name was changed to Tazewell, the name of the Custis family mansion (the home of Robert E. Lee), which is located in the county.