Final answer:
The major assertion in American history by Judith Ortiz Cofer is the impact of immigration on cultural identity, reflecting on how immigrant adaptations and identities shape the cultural landscape of the United States.
Step-by-step explanation:
The major assertion in American history by Judith Ortiz Cofer is A. The impact of immigration on cultural identity. This assertion aligns with the themes explored by researchers like Ritty Lukose, who have studied the experiences of diasporic communities and the necessity for American education systems to acknowledge immigrant identities. The emphasis on this subject suggests a focus on the influence that arriving in a new country has on one's sense of self and the cultural amalgamation that occurs as immigrants adapt to their new environment. It reflects the complex dynamics of acculturation, retention of heritage, and the emergence of hybrid identities in the context of the United States, a nation that has been profoundly shaped by successive waves of immigration.