Maryland: A possible national historic site or national monument that recognizes Underground Railroad "conductor" Harriet Tubman.
Delaware: Officials are hoping to complete a decade-long effort to bring Delaware its first national park unit (it’s the only state without one), First State National Historical Park.
New Mexico: Valles Caldera National Preserve, an 89,000-acre parcel in the Jemez Mountain Range that, despite its name, is not part of the NPS system.
Ohio: Xenia, Ohio, homesite of Col. Charles Young, the first African-American superintendent of a national park ( Sequoia National Park).
Illinois: Chicago's Pullman District, a neighborhood that played a role in the African-American labor movement.
Such discussion serves up a lesser-known point of interest regarding the National Park Service: The NPS administers more than national parks, of which 58 exist.
The other units, displayed in the chart below, include seashores, battlefields, parkways, even The White House. Trivia fans, take note:
Example National Historic Sites
Tuskegee Airmen, Alabama National Monuments
Statue of Liberty, New York-New Jersey National Parks
Grand Canyon, Arizona National Historical Parks
Chaco Culture, New Mexico National Memorials
Mount Rushmore, South Dakota National Preserves
Tallgrass Prairie, Kansas National Recreation Areas
Santa Monica Mountains, California National Battlefields
Antietam, Maryland Miscellaneous designations
White House, District of Columbia National Seashores
Cape Cod, Massachusetts National Wild and Scenic Rivers
Saint Croix, Minnesota-Wisconsin National Military Parks
Gettysburg, Pennsylvania National Rivers
Buffalo National River, Arkansas
Blue Ridge Parkway, North Carolina
Pictured Rocks, Michigan
National Battlefield Parks
Kennesaw Mountain, Georgia
National Scenic Trails
Appalachian Trail, Maine to Georgia
City of Rocks, Idaho
National Battlefield Site
Brices Cross Roads, Mississippi
International Historic Site
Saint Croix Island, Maine
Source: National Park Service. Click to see a PDF listing all 398 units.