Perhaps the forefather of the Critical Legal Studies movement, American (Legal) Realism emerged in the late 19th to early 20th century. American Realism, similar to Legal Positivism was focused primarily what the law is, as opposed to what it should be. Realists considered judicial decisions to be the crux of the law. Whilst various theorists developed their own distinct styles of Realism, they were united in their view that students of the law need to remove themselves from idealist notions and focus a more realistic view of how decisions are made.
Oliver Wendell Holmes Jr Herman Oliphant Jerome Frank Karl Llewellyn
Critical Legal Studies Legal Positivism Scandinavian Realism