The addition of the Fourteenth Amendment was necessary primarily to limit the powers held by the states, prevent unjust treatment, and ensure equal rights for all citizens. After the Civil War, there was a pressing need to protect the rights of newly freed individuals, especially African Americans, who faced systemic discrimination and violence. The Fourteenth Amendment established citizenship rights and equal protection under the law, thereby strengthening federal authority to intervene in state matters when individuals' rights were violated. This was crucial in the context of the Reconstruction era, as many Southern states enacted laws that imposed severe restrictions on the rights of freedmen.
While the Thirteenth Amendment abolished slavery, the Fourteenth Amendment was fundamentally designed to secure the legal and civil rights of individuals, particularly those who had been enslaved, by guaranteeing them the same rights and protections as other citizens. It was instrumental in laying the groundwork for future civil rights advancements and addressing the injustices and inequalities rooted in state legislation.