You should check out the one-drop rule. It is uniquely American, and it uniquely targeted African Americans for generations. It means even the smallest amount of African blood in your lineage made you fully Negro, and subject to all the class, legal and racial demotion that entailed.
Most African American families have been in the United States before it was the United States. Slave importation was made illegal in 1808, before the largest waves of Irish and English. Most white families trace their lineage to immigrants of the mid-1800's, where most black families trace their families well before the signing of the Declaration of Independence.
But no other ethic group experienced resistance by natives to integrate throughout reconstruction, and then the regression that began with Jim Crow laws at the end of reconstruction and culminated in the Civil Rights movements of the 1950's. Not merely a remembrance of history, but a glorified nostalgic reverence for the Confederacy, starting in the early 1900's, is uniquely directed at African Americans.