Region
United States
2
Hoosac Tunnel (Mass.)
1
New York (State)
1
Soldiers
1
United States--Foreign relations--Mexico
1
United States--History--Civil War, 1861-1865
1
United States--History--Civil War, 1861-1865--Engineering & construction
1
United States--History--Civil War, 1861-1865--Maps
1
United States--History--Civil War, 1861-1865--Military tactics--Union
1
United States--History--Civil War, 1861-1865--Personal narratives, Union
1
United States--History--Civil War, 1861-1865--Transportation
1