Who did John McCain quote from when he used these famous words?

Question: Who did John McCain quote from when he used these famous words!?

"!.!.!. that makes our country the greatest experiment in the history of mankind!."

I'm having trouble searching for the original quote where America was first referred to as "the greatest experiment"!.!.!. I thought it was Margaret Thatcher but it turns out the reference is much older than that!.

Can any History buffs help me out with this!?

Do you have to be as old as John McCain to remember who said it first!?Www@QuestionHome@Com

Best Answer - Chosen by Asker:

probably 18th century, try googling some more!.

also, don't just search for american history!. I'm sure someone from the middle-east, britain, asia, and other countries had said it!.Www@QuestionHome@Com

George Washington, in a letter to Catherine Macaulay Graham (a British historian of the 1700s and friend of the Washington family) January 9, 1790: "The establishment of our new government seemed to be the last great experiment for promoting human happiness by reasonable compact in civil Society!."Www@QuestionHome@Com

You have me stumped!. I have heard the phrase, but I do not know who spoke these words!. I have Googled it to no avail, except I did read some interesting experiments using chickens!.

Thomas Jefferson!?
Abe Lincoln!?
Ben Franklin!?
John Adams!?
John Kennedy!?

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