In the mid-late 1780s , Duff was living in Kaskaskia , Illinois .
Was in business with two brothers of the captain of the Ohio County , Virginia Militia and Revolutionary War Patriot , Samuel Mason who later became the notorious river pirate .
In the mid-late 1780s , Duff was living in Kaskaskia , Illinois and was in business with two brothers of the captain of the Ohio County , Virginia Militia and Revolutionary War Patriot , Samuel Mason who later became the notorious river pirate .