Elizabeth Parke Custis was born on August 21, 1776, at Mount Airy in Maryland, the home of her maternal grandparents Benedict and Elizabeth Calvert. She was the eldest daughter of John Parke Custis and Eleanor Calvert Custis and a granddaughter of Martha Washington through Martha’s first marriage to Daniel Parke Custis. George Washington was her step-grandfather. Known within the family as Eliza, she entered a wealthy and politically prominent network connecting the Custis, Calvert, and Washington households. Her earliest years coincided with the Revolutionary War. Her father served briefly in the Virginia legislature and later joined Washington’s military family during the Yorktown campaign. He died of camp fever in November 1781, when Eliza was five. Eleanor was left with four young children. George and Martha Washington took the two youngest, Eleanor “Nelly” and George Washington Parke Custis, to raise at Mount Vernon, while Eliza and her sister Martha “Patty” remained primarily with their mother. Eliza nevertheless spent substantial time at Mount Vernon and developed close relationships with her grandparents and siblings. She received the domestic and intellectual education of an elite young woman: reading, writing, music, sewing, household management, religion, and social etiquette. Family correspondence shows that Martha Washington took a strong interest in the girls’ conduct and preparation for adulthood. Her mother married Dr. David Stuart in 1783, and the expanded household eventually included many half-siblings. Eliza consequently moved within a large blended family and among several Virginia and Maryland estates. These arrangements could be affectionate but also complicated, particularly because the Custis children possessed substantial inherited property. She married Thomas Law in 1796.