Region
United States
3
Georgia
1
Haiti--Revolution, 1791-1804
1
Hoosac Tunnel (Mass.)
1
Ohio
1
Ohio River Valley
1
Philadelphia (Pa.)--Commerce
1
United States--Continental expansion
1
United States--Custom House (Philadelphia, Pa.)
1
United States--Foreign relations--Mexico
1
United States--History--Civil War, 1861-1865--Transportation
1
United States--History--Mexican War, 1845-1848
1
United States--History--War of 1812
1
United States--Territories and possessions
1