Final answer:
Natives, Mexicans, and Catholics have been marginalized by Americans. Native Americans and Mexicans suffered from systemic inequality and segregation after the westward expansion. Catholics also faced discrimination from nativists who preferred a Protestant America.
Step-by-step explanation:
The groups that would be marginalized by the Americans include Natives, Mexicans, and Catholics. Natives and Mexicans have faced profound challenges over the years. Native Americans are indigenous to the United States and have struggled with poverty, unemployment, and high rates of infant mortality, alcoholism, and suic'de. Mexicans, or Hispanic Americans, after the Mexican-American war, were treated as second-class citizens, were deprived of voting rights, faced employment discrimination, and had to attend segregated schools. Catholics and other non-Protestant groups were targeted by nativists who favored a white, Anglo-Saxon, Protestant America, which often excluded Catholics and other groups from their vision of the country.
Despite some progress, such as Native tribes winning back some control over their lands and Hispanics gaining from civil rights legislation, these groups have remained marginalized and continue to fight against discrimination and inequality. Asian Americans faced similar issues with segregation and immigration bans. Today, Latino Americans are the largest minority group yet continue to deal with topics like immigration reform and educational inequalities.