The Pilgrims of Plymouth Colony, led by governor John Carver, sign a peace treaty with Massasoit, sachem of the Wampanoags; Squanto serves as an interpreter between the two sides.

The peace treaty lasted 54 years, longer than most modern alliances. When Governor John Carver sat down with Massasoit, sachem of the Wampanoag, on March 22, 1621, both men knew they needed the other to survive. The Pilgrims had lost half their colony to disease and starvation over the winter. Massasoit's people had been devastated by European-introduced epidemics that killed roughly 90 percent of the coastal Wampanoag population between 1616 and 1619. Squanto, a Patuxet man who had been kidnapped to England years earlier and spoke English fluently, served as interpreter. His personal history was extraordinary: captured by English explorers in 1614, sold into slavery in Spain, freed by friars, he made his way to England and eventually back to his homeland, only to find his entire village had been wiped out by plague. The Pilgrims had unknowingly built Plymouth on the ruins of his town. The treaty's terms were straightforward. Neither side would harm the other's people. If anyone broke the peace, the offender would be sent to the other side for punishment. Both parties would come to the other's aid if attacked by a third party. Massasoit saw the alliance as a counterweight against the neighboring Narragansett, who had been largely spared by the epidemics and now threatened Wampanoag territory. The agreement held through Massasoit's lifetime and into his son Wamsutta's brief leadership. It collapsed only after Wamsutta's brother Metacom, known to the English as King Philip, launched a devastating war in 1675 that killed thousands on both sides and destroyed the balance of power between Native and English communities in New England permanently.