Final answer:
Due to the Spanish cruelties towards Native Americans and the Black Legend propagated by the English, it was believed that the American Indians would view the English as allies.
Step-by-step explanation:
The cruelties of the Spanish towards the American Indians during the periods of colonization were well documented, especially by figures such as Las Casas, who highlighted the severe mistreatment and exploitation of Native Americans. These accounts contributed to the creation of the Black Legend, which portrayed the Spanish as exceptionally brutal colonizers. The English, as rivals of the Spanish and also guilty of their own colonial abuses, used the Black Legend to suggest that they would be more humane colonizers. Therefore, it was believed that the American Indians would welcome the English as allies against their common Spanish adversary.