Final answer:
The 14th Amendment granted citizenship and equal protection under the law to all persons born or naturalized in the United States, including former slaves. The correct answer is option c.
Step-by-step explanation:
The United States addressed the issues of African American inequality and rights after the Civil War through a series of amendments to the Constitution, known as the Reconstruction Amendments. The amendment that specifically aimed to grant citizenship to all persons born or naturalized in the United States, including former slaves, and ensure they received equal protection under the law, is the 14th Amendment. Ratified in 1868, the 14th Amendment was a significant change in the legal and social status of African Americans, providing a broad definition of citizenship that overruled the Dred Scott decision and nullified race-based distinctions set by states regarding citizenship.
The Amendment states that "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside." This includes the Equal Protection Clause, which assures that state laws do not discriminate against individuals because they are part of a specific group. It was a key legislative act to integrate African Americans fully into American society, guaranteeing not just freedom from slavery but the rights and protections of citizenship.
Thus, the correct option is C. 14th Amendment.