MLB is governed by the Major League Baseball Constitution. This document has undergone several incarnations since its creation in 1876. Under the direction of the Commissioner of Baseball, MLB hires and maintains the sport's umpiring crews, and negotiates marketing, labor, and television contracts. MLB maintains a unique, controlling relationship over the sport, including most aspects of Minor League Baseball. This is due in large part to the 1922 U. S. Supreme Court ruling in Federal Baseball Club v. National League, which held that baseball is not interstate commerce and therefore not subject to federal antitrust law. This ruling has been weakened only slightly in subsequent years. The weakened ruling granted more stability to the owners of teams and has resulted in values increasing at double-digit rates. There were several challenges to MLB's primacy in the sport between the 1870s and the Federal League in 1916; the last attempt at a new major league was the aborted Continental League in 1960.