[EternalVigilance]

1861

1865

1870

1890

Sorry that the 1865 map is so small. It's all I could find so far.

[alfa6]

There are some nice maps here in 10 year spans. You will have to scroll down a bit to get to the maps.

http://users.humboldt.edu/ogayle/hist111/industrial.html

Regards

alfa6 ;>}