Margaret "Peggy" O'Neale (or O'Neill, later Margaret…

Margaret "Peggy" O'Neale (or O'Neill, later Margaret O'Neill Eaton), the daughter of a Washington, D.C. boarding-house owner who had lost her first husband, sailor John B. Timberlake, to suicide in 1828, is renowned for having a "vivacious" temperament—the implication being that she is overtly flirtatious and sexual at a time when "respectable" women, as a group, are not—and it has been alleged that Timberlake had been driven to suicide because of her affair with Andrew Jackson's Secretary of War John Henry Eaton.

Peggy and Eaton had been married in 1830, recently enough after Timberlake's death to scandalize the ‘respectable’ women of the capital.

The anti-Peggy coalition in what becomes known as the Petticoat Affair is led by Second Lady Floride Calhoun, the wife of Vice President John C. Calhoun, and a phalanx of other Cabinet wives, while Martin Van Buren, the only unmarried member of the Cabinet, having been widowed, allies himself with the Eatons.

Jackson is sympathetic to the Eatons, in part, perhaps, because his own beloved late wife Rachel had been the subject of equally nasty innuendo after her first marriage turned out to have not been completely dissolved prior to her wedding to Jackson.

Nonetheless, Jackson's First Lady, Rachel's niece Emily Donelson, sides with the Calhoun faction.

The scandal is so intense that several members of the Cabinet finally resigns, including Samuel D. Ingham and John Branch, and Van Buren is elevated to a position as Jackson's favorite (replacing Calhoun) and the de facto heir to the Democratic party.

Eventually, Eaton also resigns from the cabinet.

Emily Donelson is made the "Official Hostess" under Jackson.