Born to William O'Neale, the owner of a Washington boarding house and his wife Rhoda, the young Margaret and her five brothers and sisters were well known in political Washington. Leading congressmen and senators stayed at the O'Neale establishment (later called the Franklin House), and Margaret became especially popular because of her good looks and her personality. She attended one of the city's leading schools and received instruction in piano and the dance. When she became a teenager, young and old men began throwing themselves at her. After she tried to elope with one of them, her worried father put her in a boarding school in New York City under the watchful eye of DeWitt Clinton. She was there only a short time before convincing her father she should be allowed to return home.
After a whirlwind courtship, she married a navy purser named John B. Timberlake on July 18, 1816. She had three children by him, but his inability to survive financially in the store he had established in Washington forced him back to sea. She remained at home with the children, helping her family in the boarding house and the associated tavern.
Sometime during this period rumors began to circulate that she had long been a loose woman and was demonstrating this fact through an illicit relationship with a boarder, one John Henry Eaton, senator from Tennessee and close friend of Andrew Jackson. When Timberlake killed himself and she and Eaton were married soon after, this nuptial was considered more than adequate proof of her shameless immorality.
Eaton had long been close to Jackson as political advisor and friend, so, when Old Hickory entered the presidency, he named Eaton his secretary of war. Washington society and the cabinet wives were outraged that someone with Peggy Eaton's reputation was in such an important position. They refused to associate with her, basing their stand on woman's duty to protect society from immorality. The Eatons and Jackson fought a two-year battle to overcome this snubbing, and the social dispute quickly developed into a political war. In 1831 Jackson forced his entire cabinet to resign, and an irrevocable split developed between him and his vice-president, John C. Calhoun.
Failing in his effort to return Eaton to the Senate, Jackson appointed him the governor of the Florida Territory (1834-36) and later made him the United States minister to Spain (1836-40). Margaret Eaton was socially accepted in both places and when the couple returned to Washington in 1840, she received a similarly friendly reception. John Eaton established a successful law practice in the nation's capital and died in 1856.
The widow, raising the four children of her deceased daughter and son-in-law, unexpectedly married Antonio Buchignani on June 7, 1859. Though she was fifty-nine years old and he was in his early twenties, they lived an apparently happy life until the fall of 1866 when Buchignani ran away to Italy with his wife's money and her granddaughter (his stepchild). He made the mistake of returning to the United States in 1868, however, and the jilted wife had him arrested. He jumped bond, leaving her destitute. She divorced him and spent the last of her years living a difficult existence in Washington, D.C., where she died in 1879.
Margaret Eaton, The Autobiography of Peggy Eaton (1932); John F. Marszalek, The Petticoat Affair: Manners, Mutiny, and Sex in Andrew Jacksons White House (1998)