The Roosevelt years have had an unprecedented impact on the conservation policy in the United States, identifying the root causes of land degradation and encouraging the efficient "sustainable" use of natural resources. This article will attempt to show that Franklin D. Roosevelt should be considered one of the most prominent conservationist presidents in American history and highlight his significant role in the development of a federal policy on conservation. One of the main legacies of the New Deal was to federalize the responsibility of the protection of the natural resources, and subsequently that of environmental protection. Franklin D. Roosevelt was one of the first American presidents to be concerned about the degradation of the natural environment and its impact on human society. Although many modern environmentalists criticize the anthropocentric philosophy of the New Deal, the legacy of Franklin Delano Roosevelt remains fundamental, especially his active role in domestic policy. Roosevelt issued thousands of executive orders in the field of conservation, especially during his first two terms, making him much more active in this area than any other president before and after him. The interventionist approach of the Roosevelt years has remained a source of inspiration for the Democrats in the twenty-first century, proving that conservation and protection of natural resources does not need to be sacrificed in times of crisis. The first part of this article will focus on the study of the conservationist thought of Franklin Delano Roosevelt throughout his political career, first as the senator of New York, then as the governor of New York and finally as the president of the United States. The second part will focus on his agricultural and forestry programs and their visionary role during the New Deal. The last part is devoted to the study of public land management during the New Deal, such policies having influenced millions of Americans to acquire a deeper sense of personal responsibility and accept a greater role of the federal government in the field of conservation.