What movement sought to end racial segregation in the United States?

The Civil Rights Movement is the correct choice because it was specifically focused on ending racial segregation and discrimination against African Americans in the United States. This movement emerged prominently during the mid-20th century and involved a wide array of tactics, including peaceful protests, legal challenges, and advocacy for legislative change. Key figures such as Martin Luther King Jr., Rosa Parks, and Malcolm X played pivotal roles in raising awareness and pushing for civil rights.

In contrast, the Women's Suffrage Movement primarily aimed at securing voting rights for women, which, while significant, does not directly relate to the issue of racial segregation. The Labor Movement focused on improving workers’ rights and conditions, advocating for issues like fair wages and labor practices. Lastly, the Environmental Movement concentrates on issues related to the natural environment and conservation, and although it encompasses social justice aspects, it does not primarily address racial segregation. Thus, the distinction of the Civil Rights Movement lies in its core mission to combat racial inequality and promote civil rights for all individuals, particularly African Americans.