The writ's roots in the common law are described, and the provisions for habeas corpus accorded by the U.S. Constitution and by the Judiciary act of 1789 are discussed. Further, State prisoners' inability to avail themselves of Federal habeas corpus prior to the Civil War is noted. Attention focuses on the Court's early decisions interpreting the Judiciary Act, and evidence is supplied to suggest that lower Federal courts did not believe the Supreme Court's decisions on habeas corpus jurisdiction were applicable to them. The enactment of the Habeas Corpus Act in 1867 is discussed, and Congress' intent is considered. Brown v. Allen is examined as the case that firmly established that all Federal constitutional claims may be heard through the writ of habeas corpus. This decision is believed to be a sound reading of Congress' intent in the 1867 habeas corpus statute. However, the Court's decision in Fay v. Noia is criticized; the Court is believed to have adopted a view without demonstrating that it was intended by the drafters of the habeas corpus statute. The Court's decision in Stone v. Powell is determined to be consistent with the Federal habeas corpus statute. Finally, legislation before Congress to modify the habeas corpus statute is discussed. Included are 169 footnotes.