Final answer:
Squanto, a member of the Patuxet tribe, played a crucial role in helping the Pilgrims survive by teaching them local agriculture techniques and acting as an interpreter in negotiations with the Wampanoag Confederacy.
Step-by-step explanation:
The American Indian who taught the Pilgrims many things was Squanto, a member of the Patuxet tribe. Squanto's assistance was crucial for the survival of the English settlers in Plymouth. His knowledge of local horticulture, including the use of herring as fertilizer for crops such as corn, along with his ability to act as an interpreter in the Pilgrims' dealings with local tribes, particularly the Wampanoag Confederacy, were invaluable. Thanks to Squanto's efforts, a peace treaty was successfully negotiated between the Pilgrims and the Wampanoag leader Massasoit, which lasted for 24 years.