About the Site

Duplisea Duplessis and Sirois Genealogy by Mark S Duplisea



I am grateful for all of the support I have received, without which it would be impossible to continue to build a clearer picture of our family's history and genealogy.  I have corresponded with well over a hundred individuals since opening the website in September of 1999.  I have talked to a number of folks and met several cousins for the first time. It has and continues to be a wonderful experience. Below is a link to the a page which contains sources for information presented in this site along with links to any associated websites. 

Many thanks to all of you!

I want to single out some individuals who have made  significant contributions to the information presented in this website. To you I give special appreciation: 

My grandmother: 
Margaret Grace Henderson Duplisea

My grandmother did an enormous amount of  genealogy work beginning in the 1970's. She worked especially hard on our Duplisea family line, extensively interviewing our family members and traveling around Maine and New Brunswick gathering info and searching out and interviewing "Duplessis" descendants. My grandmother also introduced me to genealogy when I was 10 or 11. I dabbled then, took it back up for a year or two around 1989 and then began in earnest on this project in the summer of 1999. Her information and research notes have been invaluable in piecing together this family jigsaw puzzle. My grandmother passed away in 2011 at the age of 93.


My father:
Hugh Duplisea

In 1982 my father took a sabbatical leave from his employment and studied  French for a term at Laval university in Quebec city. While there he set about to determine the origins of  Joseph Duplessis thru research at the Quebec provincial archives. We had been unable to determine where Joseph had come from prior to establishing his family in Sunbury County, New Brunswick around 1800. My father's efforts were rewarded as help from a gracious priest who overheard his inquiries at the library desk pointed him to the Kamouraska area and the SIROIS family. A careful examination of early church records provided the missing links.  In 1984, along with my grandmother, my father published a booklet entitled " THE ORIGIN OF THE DUPLESSIS FAMILY OF NEW BRUNSWICK  -- PROPERLY CALLED SIROIS". 

Bill Duplessis
(on left) 
of Moncton, N.B. 
with Mark Duplisea

Bill is originally from the Baie Ste Anne area of Northumberland County, New Brunswick. This is where the widow of Joseph Duplessis relocated following his death. Bill did extensive research at the Centre for Acadian Studies, University of Moncton.  Most of his info comes from baptismal and marriage records of various churches.  Additional info is  from interviews he did. Bill provided me with all of his research which greatly added to the information for three of Joseph Duplessis's sons and their descendants: 

Stephen(Etienne), whose descendants are mainly in Northumberland and Kent County(Bouctouche)


Olivier, whose descendants are for the most part in Restigouche and Gloucester counties 


Benjamin, who settled in the Baie Ste Anne area and whose descendants are primarily in Northumberland County.

Additionally Bill toured my father and myself  through the Baie Ste Anne area in the summer of 2000.

Alfred Bergeron
of Hilton N.Y.
Alfred is a descendant of Michel Duplessis, eldest son of Joseph Duplessis, born to his first wife, Marie Chassť.  He is the grandson of Ida Rose Duplessis. He has done extensive research on the family surnames of each of his four grandparents and is the author of a book titled  Four French Families in America 1642-2001 which focuses on the  Bergeron, Duplessis, Blanchet, Violette and related families (Library of Congress 2001 131968).  Much of the historical information presented here on 18th century life of the Sirois dit Duplessis family in Kamouraska I have drawn from his book and other material which he has graciously shared with me. 

After  Alfred and I had corresponded and talked on the phone, he surprised me over Christmas in 2000 when he arrived on my doorsteps and presented me with a copy of his family group sheets on the Sirois Duplessis family which numbered close to 500! He has continued to provide invaluable help in this effort.
Edna (Sirois) Certo 

Germaine (Sirois) Ahearne
In June of 1991 a large group of Francois Sirois dit Duplessis' descendants gathered for a family reunion in Madawaska, Maine.  Edna & Germaine, who are sisters, gathered genealogical information thru extensive research on the Sirois/Duplessis family and added to that with information provided by attendees to the reunion. They then published The Sirois/Duplessis Family Book which contained historical information on the family as well as an extensive descendant listing. The material in  this book, which I purchased in 1999, gave me the impetus to begin the website project and to expand my focus from Joseph Duplessis to his Sirois-Duplessis ancestors.  
Henri Malenfant Henri has done extensive research on the Malenfant family. He provided me with a file containing over 500 descendants of Guillaume Malenfant and Marie Catherine Sirois (a daughter of Francois: married in 1748)
                                                                                  Henri Malenfant Website
Colin Michaud Colin has done extensive research on the Michaud family. Through a data file of his I was able to add over a thousand of Francois Sirois descendants to the database.
                                                                                    Colin Michaud Website

I hope to continue to assemble and improve upon the accuracy of the information in this site. 
If you have information which would help please contact me.
© Mark Duplisea