The historical development that led to the establishment of civil rights for marginalized communities in the U.S. can be traced to the post-Civil War era, especially the ratification of the 13th, 14th, and 15th Amendments. However, systemic racism persisted, leading to movements in the 20th century that fought against segregation and disenfranchisement. The work of key figures in the civil rights movement, combined with legislative milestones like the Civil Rights Act of 1964, transformed societal norms and expanded legal protections for minorities, laying the groundwork for contemporary civil rights advocacy.