On December 8, 1916, the President of the United States entered into a treaty with Great Britain which provided greater protection for migratory birds. Both the United States and Great Britain agreed that their legislatures would pass laws enforcing the treaty. In response, the United States passed the Migratory Bird Treaty Act of July 3, 1918 which prohibited the killing, capturing, or selling of any of the migratory birds protected by the treaty, except as permitted by additional regulations passed by the Secretary of Agriculture. Missouri (plaintiff) brought a bill in equity to prevent Holland (defendant), a United States game warden from enforcing the act. Missouri alleged primarily that the statute was an unconstitutional interference with the rights reserved to the states by the Tenth Amendment to the United States Constitution. The district court dismissed the bill on the ground that the statute was constitutional, and Missouri appealed.