Before the days of King(Assassin's Creed Fanart)

Done in 2013, After watching the trailer of DLC of The Tyranny of King Washington. IMO even if Washington acquired the piece of Eden, he was a man who had such strong mind that he was able to resist the mind control power of the holy item.
There was a proposal that Washington should be the King after the independent War of America, he could have taken that if he want. However, it seems that he fancied his farm work back in his own manor better.