From its inception as a nation in 1789, the United States has engaged in an environmental diplomacy that has included attempts to gain control of resources, as well as formal diplomatic efforts to regulate the use of resources shared with other nations and peoples. American environmental diplomacy has sought to gain control of natural resources, to conserve those resources for the future, and to protect environmental amenities from destruction. As an acquirer of natural resources, the United States has focused on arable land as well as on ocean fisheries, although around 1900, the focus on ocean fisheries turned into a desire to conserve marine resources from unregulated harvesting. The main 20th-century U.S. goal was to extend beyond its borders its Progressive-era desire to utilize resources efficiently, meaning the greatest good for the greatest number for the longest time. For most of the 20th century, the United States was the leader in promoting global environmental protection through the best science, especially emphasizing wildlife. Near the end of the century, U.S. government science policy was increasingly out of step with global environmental thinking, and the United States often found itself on the outside. Most notably, the attempts to address climate change moved ahead with almost every country in the world except the United States. While a few monographs focus squarely on environmental diplomacy, it is safe to say that historians have not come close to tapping the potential of the intersection of the environmental and diplomatic history of the United States.