 In the United States, there was historically a greater European colonial population in relation to African slaves, especially in the Northern Tier.There was considerable racial intermarriage in colonial Virginia, and other forms of racial mixing during the slavery and post-Civil War years.Jim Crow and anti-miscegenation laws passed after the 1863–1877 Reconstruction era in the South in the late-19th century, plus waves of vastly increased immigration from Europe in the 19th and 20th centuries, maintained much distinction between racial groups.