Aside from guaranteeing civil rights to former slaves, what makes the Civil Rights Act of 1866 ...

Aside from guaranteeing civil rights to former slaves, what makes the Civil Rights Act of 1866 historically significant?
 
  A) It guaranteed the rights of freedmen to marry whomever they chose, including white women.
  B) President Andrew Johnson signed the bill as a tribute to President Abraham Lincoln, whose life was cut short by an assassin's bullet.
  C) It was the first major law ever passed over a presidential veto.
  D) It was the first major racial law that southern representatives in Congress helped pass.
  E) It was the first post-Civil War legislation to have the support of both parties in Congress.