Final answer:
The Fifth and Fourteenth Amendments are pivotal to supporting civil rights protections, with the Fourteenth Amendment introducing the equal protection clause and the Fifteenth Amendment securing voting rights for Black men.
Step-by-step explanation:
The two amendments that helped provide the constitutional support for later civil rights protections are the Fifth and the Fourteenth Amendments. The Fourteenth Amendment is particularly significant, as it includes the equal protection clause and extends the due process rights of the Fifth Amendment to the states, ensuring that states respect civil liberties. It also defines citizenship at the national and state levels without discrimination based on race.
The Fifteenth Amendment was aimed at securing voting rights for Black men post-Civil War. Together, these amendments laid the groundwork for future legislation aimed at enforcing and ensuring civil rights and liberties for all citizens.