Another very prominent and successful organization (linked below) that deals with issues of racism and discrimination is the Southern Poverty Law Center, or SPLC, which monitors the activities of hate groups and those organizations that believe in, advocate and practice racial supremacy. They identify the groups and monitor their publications, and supply free legal assistance to those suffering from racial discrimination, or the victims of racist attacks.
They also publish a magainze, free to all educators, called Teaching Tolerance, which provides resources, information and materials to educators to use in the classroom and to try and stop hate before it begins.
In the United States, the group connected to the issue of racism that has been most famous historically is the National Association for the Advancement of Colored People (better known as the NAACP).
The NAACP has been around for about 100 years. It was founded by the famous black scholar and rights activist, WEB DuBois. The NAACP made perhaps its most important contribution to the fight against racism when it sponsored a series of lawsuits in the 1950s. These lawsuits led to the Brown v. Board of Education decision that ended the legality of segregated schools.
By getting this decision handed down, the NAACP got the country to the point where racism was no longer accepted as a matter of government policy.