Final answer:
Squanto's loyalty is shown through his horticultural advice and his pivotal role in establishing a peace treaty between the settlers and Massasoit, ensuring mutual aid and non-aggression.
Step-by-step explanation:
The best evidence that conveys Squanto's loyalty to the settlers from "Of Plymouth Plantation" includes his role as an interpreter and an adviser. Squanto's guidance on horticultural practices, such as using local herring to fertilize the soil, led to flourishing crops which were crucial for the settlers' survival. Moreover, Squanto's efforts in reaching an agreement between Governor Carver and Massasoit, which included terms of mutual aid in warfare and non-aggression, further showcase his commitment and loyalty to aiding the English.