Theodosia Burr was born at Albany, New York, on June 21, 1783, the only child of Aaron Burr and Theodosia Bartow Prevost Burr to survive infancy. Her mother, ten years older than Burr, was the educated widow of British officer Jacques Marcus Prevost and brought several children from her first marriage into the household. Theodosia therefore grew up within a blended family and divided revolutionary inheritance. She was raised principally in New York City, especially at Richmond Hill, the Burr estate overlooking the Hudson.

Both parents took her intellect seriously, and her father supervised an education far more rigorous than that provided to most American girls. She studied reading, writing, arithmetic, English composition, French, Latin, Greek, geography, history, music, dancing, and drawing. Tutors were expected to cultivate discipline as well as accomplishment. Aaron Burr corrected her letters in detail, pressed her to reason precisely, and treated her education as evidence that women could equal men when given comparable opportunity. Their extensive correspondence also created an unusually close father-daughter bond.

Her childhood was marked by loss. Theodosia’s mother suffered from poor health and died in 1794, when her daughter was eleven. Burr then devoted still more attention to the girl’s intellectual and social formation. By fourteen, she was acting as hostess at Richmond Hill, receiving politicians, physicians, clergy, diplomats, and visitors from the wider Atlantic world. In 1797 she presided over a dinner honoring Mohawk leader Joseph Brant while her father was absent, a demanding responsibility for a young teenager.

In February 1801, at seventeen, she married Joseph Alston, a wealthy South Carolina rice planter and politician. The marriage moved her from New York’s legal and political society into the slaveholding Lowcountry elite.