Although Caleb retains part of his real name by using the combined name of “Caleb Cheeshahteaumau,” the fact of his entry into Harvard College in 1660 is a decisive step in leaving his own Wampanoage (Wopanaak) culture. All the colleges in what became the US were run by colonial powers and had a tiny handful of non-Euro-heritage students, who were in highly segregated conditions.
Long before starting college, however, Caleb began his assimilationist journey into the Puritan realm. Befriending Bethia can be considered one step, including his accepting the idea of her book as property. Brooks, however, presents their friendship as a two-way street which includes Bethia learning Caleb's language as well.
Literacy, through tutoring with an English-heritage colonist—Bethia’s father, Pastor Mayfield— was one important step. These lessons included catechization and renaming, consistent with the pastor’s goals of conversion/salvation. The staunchly Protestant Puritans further imposed cultural norms of hygiene and dress. Learning also included living in the teacher’s household in the Anglo town of Great Harbor. Another significant point comes when Caleb insists on speaking English only.
The literal crossing, when he was sent from Martha’s Vineyard to mainland Massachusetts to continue his study, is another significant step away from his culture.