Northampton County probably was named for the English county, of which Obedience Robins, a prominent early resident of the Eastern Shore, was a native. The county, which originally included all of the peninsula south of Maryland and which was one of the eight shires established in 1694, was first called Accomac. The name was changed by legislative action in 1643.

In seventeenth- and eighteenth-century Virginia, the term "tithable" referred to a person who paid (or for whom someone else paid) one of the taxes imposed by the General Assembly for the support of civil government in the colony. In colonial Virginia, a poll tax or capitation tax was assessed on free white males, African American slaves, and Native American servants (both male and female), all age sixteen or older. Owners and masters paid the taxes levied on their slaves and servants. For a more detailed history of tithables, consult the Library of Virginia's website for Colonial Tithables