Region
United States
491
Colorado
146
New York (State)
127
Pennsylvania
92
Massachusetts
84
California
74
Washington (State)
52
New Mexico
47
Georgia
44
Texas
38
Ohio
37
Washington (D.C.)
37
Virginia
36
Kansas
33
Maryland
32
Arizona
31
Montana
29
Missouri
28
New York
27
West (U.S.)
27
Alaska
26
Illinois
26
Arkansas
25
New Jersey
25
Connecticut
24
Tennessee
23
Louisiana
22
North Carolina
22
South Carolina
22
Springfield
21
Utah
21
Grant-Kohrs Ranch National Historic Site (Mont.)
20
Hawaii
20
John Muir National Historic Site (Calif.)
20
Wyoming
20
Atlanta
19
South Dakota
19
Sagamore Hill National Historic Site (Oyster Bay, N.Y.)
18
Hyde Park (Dutchess County)
17
Kentucky
17
Martin Luther King, Jr., National Historic Site (Atlanta, Ga.)
17
Oklahoma
16
Salem Maritime National Historic Site (Mass.)
16
Fort Davis National Historic Site (Tex.)
15
Manzanar National Historic Site (Calif.)
15
North Dakota
15
Sand Creek Massacre National Historic Site (Colo.)
15
Dayton Aviation Heritage National Historical Park (Ohio)
14
Florida
14
Idaho
14
more ...