In the New Mexico-Arizona Enabling Act (Enabling Act) the federal government granted to Arizona certain parcels of land for public schools. The grant was subject to certain conditions, including that the land could only be sold or leased to the highest bidder at an advertised public auction, and only for at least an appraised value. The Enabling Act excluded mineral lands from the grant, but did not address lands on which minerals were found later. This resulted in myriad disputes about whether certain lands were covered. To resolve this, Congress passed the Jones Act, which extended the Enabling Act to mineral lands. An Arizona statute regarding leases of state mineral lands did not require advertisement or appraisal before the lands were leased. Kadish and other Arizona taxpayers (plaintiffs) brought suit against the Arizona Land Department and ASARCO Inc. and other lessees of state lands in Arizona (defendants). The plaintiffs claimed that the Arizona statute was void because it did not conform to the conditions in the Enabling Act. The defendants argued that the conditions in the Enabling Act did not apply to any mineral lands granted under the Jones Act. The trial court upheld the state statute. The Arizona Supreme Court reversed, finding the statute void. The United States Supreme Court granted certiorari.