The tribes argued that, historically, tribes had jurisdiction over all Indians regardless of membership. For example, federal statutes used the word "Indian" without regard to membership, to refer to the "family of Indians." Courts of "Indian offenses," established by the Department of the Interior for tribes without their own functioning court systems, historically exercised jurisdiction over all Indians without regard to membership, and continue to do so. But the Court responded that federal statutes had always referred to federal programs, and never to the power of tribes with respect to individual Indians. "The historical record prior to the creation of modern tribal courts shows little federal attention to the individual tribes' powers as between themselves or over one another's members. Scholars who do find treaties or other sources illuminating have only divided in their conclusions." After the federal government allowed the tribes to "express retained tribal sovereignty" by creating their own tribal courts, the Secretary of the Interior still had to approve the legal codes the tribes created before the courts of Indian offenses would yield to the tribes own courts. Written opinions of the Solicitor General of the Department of the Interior consistently affirmed the power of the tribes over their own members, but went no further. In light of the historical record, the Court was not "persuaded that external criminal jurisdiction is an accepted part of the courts' function."