Cadillac was born at St. Nicolas de la Grave, France. Little is known of his early life. Though he made every effort to convince people that he was possessed of an aristocratical background,1 it is likely that he was born to a middle class family.
We first take note of Cadillac (then simply known as Antoine de Laumet) at Port Royal, 1683. The DCB simply states that he "landed in Acadia as an obscure immigrant and settled in Port-Royal." From a reading of Webster's account one would get the impression that Cadillac might have come over as a member of the French military forces to take a position in the French garrison.2 I believe this to be unlikely in view of his considerable freedom to do what he liked.3 Initially, I am sure that Cadillac would have impressed the local officials as an energetic young man who might be of considerable service to the small struggling colony.
Soon, at Port Royal, Cadillac was to meet the privateer, François Guyon4. Guyon knew a good hand when he saw one and recruited the young Cadillac to sail with him on his numerous forays down the New England coast. Guyon took a shine to Cadillac and showed him the ways of the sea and taught him the art of navigation. François Guyon, as we see elsewhere, while often calling in and out of Port Royal, did not live in Acadia, but in Quebec. At the end of the sailing season Guyon would travel back to his home village at Beauport. And, at least in one season, Guyon was to bring his young protege back to Beauport with him. It was during one of these seasonal visits that Cadillac was to meet, and, in 1687, to marry Guyon's niece, Marie-Thérèse Guyon.
Likely through the offices of the Guyon family, Cadillac was to secure a seigneury (a grant of land) on the Douaguek River (Union River, State of Maine); and, he and Marie-Thérèse relocated back to Acadia. It would not appear that Cadillac was too keen on cutting out a living in the wilderness; he was soon developing trading connections at his familiar stomping grounds at Port Royal.5 Cadillac's trading activities were soon to get him in to difficulties with the authorities at Port Royal. Meneval was to write of Cadillac in one of his dispatches: "This Cadillac is the most uncooperative person in the world, is a scatter-brain who has been driven out of France for who knows what crimes."6
Sir William Phips, in 1690, brought ruin to Acadia. There was not much left for the Acadian inhabitants to do but to pick up the pieces and set to work again; to rebuild and to re-establish themselves on the land, yet again. Cadillac, with his trading connections severed, thought it easier, however, to pull up stakes and move. He left Acadia, and, from what I can see he was never to return.
Cadillac went to Quebec, sought out Frontenac and thereafter made his most lasting impressions on the historical record. Between the years 1694-97 Cadillac was the commandant at Michilimackinac. In 1701, he built Fort Pontchartrain (thus he founded Detroit), a fort which he was to command for several years. In 1707, he led a force against the Miamis and brought them to terms. In 1713, he took up his position as the governor of Louisiana. In 1717, Cadillac returned to France there to take up his position as the Governor of Castel Sarassin, in Gascony, his native province. Cadillac died in Gascony on October 16th, 1730.
Boastful, ingenious, glib, boisterous, arrogant, quarrelsome, and "one of the worst scoundrels ever to set foot in New France", Cadillac is one of the most memorable characters to be found in early Canadian history. He was unquestionably just the kind of person that was required in the successful French efforts to sink its taps deep into the western frontier and to effectively deal with the people to be found there.7
 It was a common occurrence, during the days when it was not quick or easy to check stories, for young men of European birth on coming to America, in an effort to establish good connections to the authorities in the new world to boast of their special connections back in the old world. What has been speculated is that Cadillac did receive a better than usual education for his "voluminous American correspondence" was "invariably witty and well written."
 In 1686 there was but 30 soldiers at Port Royal, quartered on the inhabitants.
 There is no evidence that Cadillac had any official attachment to the military during his first years at Acadia though he likely, if not with François Guyon on the high seas, would have been in the militia and therefore would have played a role for the French when Phips took Port Royal for the English in 1690. Certainly after his arrival at Quebec in 1691, Cadillac was made, by Frontenac, a lieutenant in the colonial regular troops.
 See the DCB, vol. II, p. 271.
 Mathieu de Groutin was to become one of his trading partners.
 As quoted by the DCB.
 In 1692, Cadillac wrote his memoirs which were translated by Dr. Ganong and can be found in the collections of the N.B. Hist. Soc, no. 13, 1930. For more on Cadillac see DCB's entry and see Webster's work on Villebon, pp. 167-8.