After leaving the Republic of Geneva, he spent more than a decade in the West Indies before moving to New York and then Philadelphia.
Du Simitiere was the translator into French for the Letters to the inhabitants of Canada from the Continental Congress designed to draw the new British subjects of Quebec into the American Revolutionary War.
In his efforts to achieve his objectives, he fought a constant battle with poverty and with the lack of interest of persons who might have helped him gather materials.
In a measure he realized his vision briefly in his 'American Museum,' located in a house in Arch Street above 4th, which he advertised as early as September 1782.
"[4][excessive quote] He created the first American museum of natural history from his personal collections constituted during his travels and through his purchases.
[5] His coin collection was the first record in Early American history to serve as collateral on a loan granted to him by William Dilwyn.
Included in the sale as Lot #19 was "A Mahogany cabinet containing ancient and modern Gold, Silver, and Copper Coins and Medals.
He cuts out of the Newspapers, every Scrap of Intelligence, and every Piece of Speculation, and pastes it upon clean Paper, arranging them under the Head of the State to which they belong and intends to bind them up in Volumes.