This is not one of my lines; however, I know your line supposedly was part of the Mennonite families - (Luthern earlier) that removed out of Switzerland and Austria - resettled in German lands - then finally ended up in a Pennsyvania Mennonite community. The spelling on your name has changed dramatically - there are many varitions of it.
Your particular spelling - Gnagy - left Penn. moved into Indiana - one branch (my step-father's) traveled further into Nebraska - and ended up in Kansas. Because of the spelling of your name - and the route your ancestors took leaving Penn. I suspect you are a part of this earlier "Kansas" group.
Besides hooking up with the Nebraska/Kansas "Gnagy"s - you might take a look at the following post/website.
Barbara wife of Jacob KNEGI:
http://www.rootsweb.com/~paberks/wills/wilab10.htmlDo a "edit" then "find" down to:
YODER, JOHANNES - in it he mentions a relation of yours.
Hope this gives you some good leads.
Lots of luck