American culture - Race relations

African-Americans are mostly descendants of African slaves imported to the United States. Slavery was partially abolished by the Emancipation Proclamation issued by president Abraham Lincoln in 1862 for slaves in the Southeastern United States during the Civil War and the defeat of the secessionist Confederate States of America. Slavery was rendered illegal by the passage of the Thirteenth Amendment to the United States Constitution. Jim Crow Laws prevented full use of citizenship until the 20th century. The Civil Rights Movement in the 1960s and the Civil Rights Act of 1964 outlawed official or legal segregation in public places or limited access to minorities. A large majority of Americans of all races disapprove of racism. Nevertheless, some Americans whom self-identify themselves white, black, Latino, Asian, American Indian, and Pacific Islander, continue to hold negative racial/ethnic stereotypes about each other based on a social group of people they belong to. Professor Imani Perry, of Princeton University, has argued that contemporary racism in the United States "is frequently unintentional or unacknowledged on the part of the actor.” She believes that racism mostly stems from unconsciously below the level of cognition.