Catherine Mercer (1707-1750) was a member of a prominent Revolutionary-era family and the spouse of John Mercer. John Mercer was a writer, planter and estate manager, and lawyer whose career or family position supplies an important part of this entry’s Revolutionary context. The marriage connected Catherine Mercer to the political, military, commercial, or social developments surrounding the Revolution. Although this life ended before the fighting for independence began, the marriage and family connections formed part of the colonial society inherited by the Revolutionary generation. Surviving documentation is strongest in genealogical, family, estate, and marriage records rather than in a separate public biography. Including Catherine Mercer in HistoryGPS recognizes that households, marriages, property, correspondence, hospitality, and kinship networks were essential parts of the world in which Revolutionary leaders acted.