South Dakota:
http://alabamamaps.ua.edu/historicalmaps/us_states/southdakota/index.html
http://www.historicmapworks.com/Browse/United_States/South%20Dakota/
http://www.davidrumsey.com/luna/servlet/view/search?q=South+Dakota&sort=Pub_Date,Pub_List_No,Series_No
http://alabamamaps.ua.edu/historicalmaps/us_states/southdakota/index.html
http://www.historicmapworks.com/Browse/United_States/South%20Dakota/
http://www.davidrumsey.com/luna/servlet/view/search?q=South+Dakota&sort=Pub_Date,Pub_List_No,Series_No