Recently I've come across a great deal of evidence (too much for me to document) of Founding era figures speaking to unconverted Natives, addressing God as "The Great Spirit." I'm not sure how much or what to make of it.
Here is my latest find from Rufus Putnam. Speaking to the Natives in 1792:
I thank the great Spirit who has inclined our Hearts to do good; and to establish a Peace between You and the United States — Brothers
Let us endeavour to restore Peace and happiness to all as far as lies in our Power; and for this purpose I request that You will send a Speech to Your Neighbours the Miamis, Dellawares, Shawanos and other Tribes, who have hitherto stopped their Ears, and refused to Speak with the United States about Peace; altho many Speeches have been sent to them for that purpose — Brothers,
I propose to send one Speech more requesting them to open a Road to some place or other, where we may meet and Speak to one another; And I trust with Your assistance, that the great Spirit will cause this good Work to succeed —