The following explanation of the "dit" name was in an old book called Cadillac's Village by C.M. Burton. Burton was an historian in Detroit and had corresponded with Fr. Christian Denissen in regards to the French names in Detroit. The letter dated 9 Nov 1896 is from Fr. Denissen to Burton and in part goes like this:
1) The early colonists of Lower
Canada obtained from the French government grants of extensive tracks
of land. These grants were executed in the medieval phraseology used under
the feudal system of holding estate.
In some cases these titles
were confirmed by the government. The owners of these vast estates considered
themselves "seigneurs" of their new country, and were very proud
of the affixes to their names. In business transactions these additions
to their signatures were used with all their flourishes.
At baptisms the title had to
be entered in the parish registers; at marriages the affix to the old
family name sounded high both for the bride and groom in the verbose marriage
contract; respectability was increased by the presence of many witnesses
with titled names.
2) Another cause of the change
of French names was the custom so prevalent in former times, of nicknaming
themselves and others. This was done sometimes to discern one family from
another of the same name; as a family Baron was nicknamed Lipien - Baron
dit Lupien - to distinguish it from other Baron families, Lupien being
the Christian name of the ancestor of that family in this country.
At other occasions the nickname
originated through family pride; when a member was distinguished, that
branch of the family would annex the Christian name of the hero, or, if
a woman, the family name of the revered heroine. In this manner some Cuilleriers
lost their own name through the marriage of John Cuillerier with Mary
Catherine Trotier de Beaubien; this lady was distinguished through her
family title of Beaubien, and after John cuillerier's death, by becoming
the wife of Francis Picote de Belestre, an officer of Fort Ponchartrain.
On this account her children from the first marriage signed themselves
Cuillerier dit Beaubien, and in later generations Cuillerier was dropped
and nothing was left but Beaubien. There are nicknames that originated
from the peculiar circumstances of birth, like Nicolas Campau dit Niagara,
who was born at the Portage of Niagara, when his parents were traveling
from Detroit to Montreal. It happened, also, that nicknames were given
by Indians, as Labadie dit Badichon, Peltier dit Antaya.
Nicknames have also been given
frivolously and would stick in future generations, as in the family of
Poissant, sounding like Poisson (fish), by adding Lasaline (salt), Poissant
dit Lasaline (saltfish). Another way of nicknaming was by adopting a peculiar
Christian name by which a certain person was known in the community; so
we find the family of Le Tourneux, a Jean-Baptiste Le Tourneux, who settled
in Sandwich, opposite the Michigan Central Depot of present Detroit, about
110 years ago. He was known by everyone as Jeannette (the diminutive name
of Jean); by incorrect spelling he became Janet and Janette, hence, Le
Tourneux dit Janette. His numerous descendants are called Jannette. Other
modes might be mentioned. It is singular that scarcely a name has been
adopted from the trade, occupation or profession that a person followed.
These nicknames are attached to the name proper by the word "dit"
which might be rendered in our language by "called", "named",
"namely", "to wit", "known as", but "dit"
is so idiomatically French that it can hardly be translated into English.
The suppression of "s" in some names, as from Chesne to Chene,
Estienne to Etienne, is accounted for by the evolution of the French language
from the old form to the modern way of spelling.