Filippo Mazzei, also known in English as Philip Mazzei, was an Italian physician, philosopher, diplomat, winemaker, merchant, and author. A close friend of Thomas Jefferson, he was a strong supporter of the American Revolution and independence from Britain.
In 1774 he published a pamphlet containing the phrase, which Jefferson incorporated essentially intact into the United States Declaration of Independence, "All men are by nature equally free and independent." Translated by Jefferson as follow, “All men are by nature equally free and independent. Such equality is necessary in order to create a free government. All men must be equal to each other in natural law.”
In 1779 he accepted a commission from Patrick Henry, the Virginia governor, to seek a loan from the grand duke of Tuscany and to gather useful political and military information for Governor Jefferson.
He died in Pisa in 1816, without ever returning to America. After his death the remainder of his family returned to the United States at the urging of Jefferson. They settled in Massachusetts and Virginia.
He was buried at the Suburbano Cemetery in Pisa.