Wresting Control Of The Western Country

From The Kentuckians by Janet Holt Giles:

Major [George Rogers] Clark said....Dave, it's my opinion that we should strike at the source of this trouble.

Now, where are the British in the western country?  Well, mostly over in the Illinois country.  They've got that fort at Kaskaskia now, and one or two more.  Exactly.  And Hamilton is at Detroit, in charge of them all.  Dave, if we can strike at the Illinois forts, and then drive on Detroit, we shall win our war in the west!