State of Missouri v. Holland

The National Wildlife Refuge System of the United States is an outgrowth of environmental concerns elicited by the rapid disappearance of bird species such as the tern, the egret, and the heron during the late nineteenth century. The Committee for the Protection of North American Birds of the American Ornithologists' Union urged President Theodore Roosevelt to take action. In 1903, he established the nation's first bird refuge at Pelican Island Reservation in Florida. Under Roosevelt's administration, the refuge system for wildlife expanded. In 1908, Congress initiated the purchase of a bison range in Montana, and by 1930 the federal government owned some 5 million acres of wildlife-refuge land, on which it operated 86 refuges.

As part of this push toward environmental awareness, the United States in 1916 signed the Migratory Bird Treaty with Canada. The treaty established the importance of protecting species flying back and forth between countries and set up a foundation whereby the federal government would manage and maintain migratory wildlife. This was followed by the Migratory Bird Conservation Act of 1929 and the Migratory Bird Hunting Stamp Act of 1934.