Final answer:
The Civil War amendments laid the groundwork for African American rights, but were not fully effective until the mid-20th century with additional legislation. Even then, further measures like a federal anti-lynching law could have strengthened protections against racial violence.
Step-by-step explanation:
The amendments passed after the Civil War, specifically the 13th, 14th, and 15th amendments, were a significant starting point for granting African Americans their rights. However, these rights were not fully safeguarded until much later. The Fourteenth Amendment, while providing equal protection under the law and defining national and state citizenship, was often undermined by states' actions and Supreme Court interpretations such as Plessy v. Ferguson which upheld segregation. The Fifteenth Amendment guaranteed the voting rights for African American men, but for many years, tactics like literacy tests and lynching, prevented the full exercise of these rights. It wasn't until the civil rights movement, exemplified by the 1965 Voting Rights Act which banned literacy tests and the 24th Amendment which eliminated the poll tax, that substantial protections were enforced.
An additional protection that could have been passed by the federal government to protect African Americans might have been a federal anti-lynching law, which was lobbied for tirelessly by leaders like Ida Wells but never made into law due to opposition. Such a law could have provided a crucial step towards undermining the culture of impunity surrounding racial violence.