Brett Rushforth, "Slavery, the Fox Wars, and the Limits of Alliance," William and Mary Quarterly 63 (January 2005), No.1, para. 32. Rushforth confuses the two Vincennes explorers.
François-Marie was 12 years old during the First Fox War.
jstor.org
Kenneth M. Ames, "Slaves, Chiefs and Labour on the Northern Northwest Coast," World Archaeology, Vol. 33, No. 1, The Archaeology of Slavery (Jun., 2001), pp. 1-17 in JSTOR