9 books
The American Postal Network, 1792–1914 Vol 3
The American Postal Network, 1792–1914 Vol 1
The American Postal Network, 1792–1914 Vol 4
The American Postal Network, 1792-1914
The American Postal Network, 1792-1914 Vol 2
Network Nation
Ruling Passions
Spreading the News
Managing Big Business