The group that gained more political participation when amendments were added to the Constitution is African Americans.
Key amendments that expanded political participation for African Americans include the 15th Amendment, which prohibits denying the right to vote based on race, and the 19th Amendment, which granted women the right to vote, benefiting African American women as well.
Native Americans did not gain full citizenship rights until the Indian Citizenship Act of 1924 and were often still denied the right to vote through state laws even after that. Asian Americans faced significant barriers to citizenship and voting rights until the mid-20th century.