Interracial marriage in the United States has been fully legal in all U.S. states since the 1967 Supreme Court decision that deemed anti-miscegenation state laws unconstitutional, with many states choosing to legalize interracial marriage at much earlier dates. Anti-miscegenation laws have played a large role in defining racial identity and enforcing the racial hierarchy. The United States has many ethnic and racial groups, and interracial marriage is fairly common among most of them. Interracial marriages increased from 2% of married couples in 1970 to 7% in 2005 and 8.4% in 2010.