Bruce; I was thinking about the dates after I posted my message. Instead, try pasting this link into your browser:
http://lcweb2.loc.gov/cgi-bin/query/D?gmd:1:./temp/~ammem_sJ...::
It is a circa 1876 map of railroads from NYC to the West posted on the Library of Congress - American Memory site. Surf around there, the fishing is good.
Also try
www.migrations.org and surf through the links.
Good luck and good hunting.
JW