It was just a broken plate found buried in a trash heap. But to researchers at James Madison's estate, Montpelier, fragments of porcelain unearthed last month from the Virginia piedmont tell a story of a first lady, two U.S. presidents, a king and queen and the revolutions that bind their legacies more than 200 years later.

Discovered amid oyster shells, a chamber pot and shards of glass that filled a midden, or trash pile, near Dolley Madison's kitchen, a fractured dessert plate found by researchers during a $24 million restoration of Montpelier is believed to date to the late 1700s and might have once belonged to Marie Antoinette, the French queen with an infamous penchant for decadent living who perished at the guillotine during the French Revolution.