Among the possessions of the State Library is a large collection of letters and other papers, some of them originals, some copies, that relate to Vincennes during the early American occupancy. These documents were gathered up by the late Charles B. Lasselle, of Logansport, who for many years was an industrious collector of everything pertaining to French life in the Wabash Valley. Mr. Lasselle was himself a member of an old French family that had been intimately identified with the valley since Revolutionary times. In his later years he occupied a room in the Court House at Logansport which was fairly filled with a miscellaneous mass of documents, relics and newspapers. Among the relics were the mahogany liquor chest which was one of Governor Hamilton's private possessions when he was captured by Clark; a Revolutionary drum that had been found in old Fort Wayne, and the original parchment document that was delivered to the Miami Indians at the treaty of St. Mary's, in 1819. This parchment bears the mark of the various chiefs that represented their tribe, and the signatures of Jonathan Jennings, Benjamin Parke, and Lewis Cass, commissioners, and William and John Conner, interpreters. It was delivered to the Miami head chief, Richardville, and finally came into the Lasselle family through marriage relations. It is now in the possession of the Indiana State Library.

The other documents referred to as in the library are now being classified and arranged for convenient reference.