Theodore Roosevelt, the greatest environmental and conservation President, promoted the passage of the Antiquities Act of 1906, and since then, 16 Presidents have designated a grand total of 157 National Monuments and National Parks.
Four Republican Presidents added no national monuments or national parks—Richard Nixon, Gerald Ford, Ronald Reagan, and George H. W. Bush, although Nixon is seen as a great environmental President with his Secretary of the Interior Walter Hickel, and the signing into law of the Environmental Protection Agency in 1970, and the first declared Earth Day on April 22, 1970.
Under Theodore Roosevelt, a total of 18 monuments or parks were added, including Devils Tower National Monument, Petrified Forest National Park, Muir Woods National Monument, Grand Canyon National Park, and Olympic National Park.
William Howard Taft added 10 national monuments and national parks, including Navajo National Monument and Zion National Park.
Woodrow Wilson added 13 national monuments and national parks, including Dinosaur National Monument, Acadia National Park, and Casa Grande Ruins National Monument.
Warren G. Harding added 8 national monuments and national parks, including Great Basin National Park, Aztec Ruins National Monument, and Bryce Canyon National Park.
Calvin Coolidge added 13 national monuments and national parks, including Carlsbad Caverns National Park, Statue Of Liberty National Monument, Fort Pulaski National Monument, Castillo de San Marcos National Monument, Natchez Trace National Scenic Trail, and Glacier Bay National Park and Preserve.
Herbert Hoover added 9 national monuments and national parks, including Arches National Park, Portion Of White River National Forest, Great Sand Dunes National Park and Preserve, Grand Canyon National Park (extension), White Sands National Monument, and Death Valley National Park.
Franklin D. Roosevelt added 13 national monuments and national parks, including Dry Tortugas National Park, Joshua Tree National Park, Zion National Park (extension), and Grant Teton National Park.
Harry Truman added just 1 national monument and national park, Effigy Mounds National Monument.
Dwight D. Eisenhower added just 2 national monuments and national parks, Thomas Edison National Historical Park, and Chesapeake and Ohio Canal National Historical Park.
John F. Kennedy added just 2 national monuments and national parks, including Russell Cave National Monument, and Buck Island Reef National Monument.
Lyndon B. Johnson added just 2 national monuments and national parks, an extension again of Grand Canyon National Park, and Portion of Tongrass National Forest.
Jimmy Carter added 15 national monuments and national parks in just one term as President, a reason why Carter is seen as one of the top three conservation oriented Presidents, alongside TR and Nixon. Among those monuments and forests Carter added were Denali National Park in Alaska, Gates of the Arctic National Park and Preserve, and Yukon Flats National Wildlife Refuge.
Bill Clinton added the grant total of 19 national monuments and national parks, including Grand Staircase-Escalante National Monument, California Coastal National Monument, Grand Canyon-Parashant National Monument, Portion of Sequoia National Forest, President Lincoln and Soldier’s Home National Monument, Sonoran Desert National Monument, Virgin Islands Coral Reef National Monument, and Governors Island National Monument.
George W. Bush added 6 national monuments and national parks, including African Burial Ground National Monument, World War II Valor in the Pacific National Monument, and Pacific Remote Islands National Monument.
Finally, Barack Obama added the grand total of 29 national monuments and national parks, far more than runners up Bill Clinton, Theodore Roosevelt, Jimmy Carter, Woodrow Wilson, Calvin Coolidge, and Franklin D. Roosevelt. These included Fort Monroe National Monument, Cesar E. Chavez National Monument, San Juan Islands National Monument, Rio Grande del Norte National Monument, Harriet Tubman Underground Railroad National Historical Park, San Gabriel Mountains National Monument, Stonewall National Monument, Bears Ears National Monument, Birmingham Civil Rights National Monument, Freedom Riders National Monument, and Reconstruction Era National Monument.