During Reconstruction, several significant amendments were added to the U.S. Constitution, notably the 13th, 14th, and 15th Amendments. The 13th Amendment abolished slavery, marking a crucial step towards civil rights. The 14th Amendment granted citizenship to all persons born or naturalized in the U.S., ensuring equal protection under the law and addressing issues related to former slaves. The 15th Amendment aimed to secure voting rights for African American men, prohibiting states from denying the vote based on race, color, or previous condition of servitude. These amendments laid the groundwork for future civil rights advancements and transformed the social landscape of the nation.