A new exhibition that opened Friday in Plymouth, Massachusetts, highlights this other slave history. It’s an integral part of the town’s preparations for the 400th anniversary of the Pilgrims' arrival in 1620, and it focuses on the story of one man in particular: Squanto.

You might remember Squanto for his role in the Thanksgiving legend. He stepped out of the woods in the spring of 1621 and greeted the Pilgrims in perfect English. He became their interpreter and guide, and helped negotiate a treaty with the most powerful local Native American confederation, a peace that lasted more than 50 years.

The colony’s governor and first historian, William Bradford, wrote that "Squanto continued with [the Pilgrims] and was their interpreter and was a special instrument sent of God for their good beyond their expectation. He directed them how to set their corn, where to take fish, and to procure other commodities, and was also their pilot to bring them to unknown places for their profit, and never left them till he died."

What’s less well-known is how he came to learn English, and why he was there at the right place and time.