When President Theodore Roosevelt issued an executive order making Pelican Island, Florida, a federal bird reservation, he introduced the idea of a national wildlife refuge. Nearly 90 years later, Roosevelt's action has expanded to a system of more than 400 national wildlife refuges with a combined area of over 90 million acres (36 million ha).

Roosevelt's action was aimed at protecting birds that used the islands. Market hunters had relentlessly killed egrets, herons, and other aquatic birds for their feathers or plumes to adorn women's fashions. The first national wildlife refuge, like other conservation practices of the early twentieth century, emerged in reaction to unregulated market hunting. Pelican Island became a sanctuary where wild animals, protected from gunfire, would multiply and then disperse to repopulate adjacent countryside.

States followed suit, establishing protected areas known variously as game preserves, sanctuaries, or game refuges. They were expected to function as breeding grounds...