On February 2, 1704, Marie Therese Cadillac, daughter of the city’s founder, became the first child baptized in Detroit. She is born 9 months to the day that her mother arrived in Detroit from Montreal to join her husband on the frontier.
Source : Detroit Historical Society Facebook Page and the Detroit Almanac.
Bonus: Younger readers might want to pursue First Lady of Detroit: The Story of Marie-Thérèse Guyon, Mme Cadillac (Detroit Biography Series for Young Readers), a book about Marie Therese Cadillac’s mom. First Lady of Detroit is a spirited tale of an adventurous girl who grew up to commission and equip her own expedition to le Detroit, joining her husband there in the fall of 1701-less than a dozen weeks after Fort Pontchartrain was carved out of the wilderness.