Have you tried Googling? I found these sites, which may be of interest:

http://en.wikipedia.org/wiki/Cornish_diaspora

http://www.bbc.co.uk/legacies/immig_emig/england/cornwall/

www.casa.ucl.ac.uk/surnames/papers/20_cornish_migration.pdf

http://www.cornishfest.org/the_great_migration.html

http://chycor.co.uk/murdoch-house/connect1.htm

http://www.bbc.co.uk/legacies/immig_emig/england/cornwall/ar...

http://onlinenevada.org/cornish_immigrants


It sounds like you're just guessing about Samuel JAGO's parents. Perhaps delving further into American records might provide you with more information.

Good luck!