Research Guide

The Cassidy name, including its variations, is not very common. The origins of the clan are well documented and go back to 12^th Century Ireland. So if your surname is Cassidy or you have Cassidys in your family tree, then we are most likely related somehow. The question is how? Where do our family trees connect?

As expected, the trail gets harder to follow as you go back in time. When you get to Ireland, as you most certainly will, it gets particularly difficult due to the sketchiness of public records. Nonetheless, with patience and perseverance connections can be found. Our ancestors left Ireland in 1819 and so far we’ve managed to trace the family within Ireland back to 1705.

The Cassidys of Cassidy Lake

Our branch of the Cassidy family originates with William Cassidy who was born in County Donegal in Ireland in 1797. In 1819 William and his wife Jane Milligan emigrated to New Brunswick, Canada and in 1823 settled beside a small lake in south central New Brunswick which eventually became known as Cassidy Lake. Initial migrations from New Brunswick in the late 1800s and early 1900s were to central and western Canada (Ontario and British Columbia) and to the United States (New England / Boston area, California and Montana). If you can place your branch of the Cassidy family near these geographical areas, the more likely we are related.

Searching for the Connection

Things to look for in your search:
Names: First, Middle and Last
Dates: Birth, Death, Marriage
Ancestors: Parents, grandparents
Siblings
Life History: Religious affiliation, occupation, residence, military service, etc.

DNA Matching

One way to improve the probability that people are related is through DNA matching. We’ve been exploring this science to better understand its uses and limitations. I (Peter Cassidy) have had my DNA tested by Family Tree DNA. They have a Cassidy project which I have joined. It compares the DNA of all Cassidys they have tested. If you have Family Tree DNA test your DNA and you join this project, you can see how closely our DNA matches. The more common way to use DNA testing is for two people to have their DNA tested and see how they compare. Here are some things we’ve learned about using DNA testing:

As a rule, only males should be tested as men and only men inherit their father’s Y-Chromosome.

Family Tree DNA offers several levels of DNA testing. The 37 marker test is the least expensive and sufficient for identifying the haplogroup you are in and the percentage of chance you are related within a certain number of generations.

The following documents explain DNA testing in more detail:

• Understanding DNA
• Understanding Matches
• Understanding Your Y-DNA37 Results

About Names and Dates

The first step is to do a name search in our genealogy record on this website. Until we establish a definite family connection, your search will be limited to the Public records section. The difference between the Public and Members section is that the public section does not have dates, narrative, or photos for persons still living. Unless we have death dates, our records assume persons less than 100 years old are still alive. In any case, all our known family members are listed in the Public genealogy record. If you find a definite connection, sign up for access to the members section and view additional information about your relatives.

Finding a name match may not be enough. Cassidys in Ireland share and reuse given names a lot so you might have the right name but the wrong branch of the family. You might have the right branch but the wrong generation. It’s important to also examine dates, and wherever possible, life history.

Life History

You can narrow the field considerably knowing something about the person’s life history. Protestant vs. Catholic religious affiliation is a major separator of family branches through the 1800s. The original clan members were Catholic, but somewhere along the way some became Protestant and that proved to be a major divide in family relations especially in Ireland.  Newspaper articles, including obituaries, are helpful in providing insight to a family member’s full identity. Allow for misspellings and use of nicknames or middle names even in official government records. Towns mentioned may go by several names.

Perhaps We Can Help

If you suspect a connection, but are not sure, drop us an email and we’ll peruse the records for you. We’ll use our access to the narrative in the Members section looking for clues. In our work over the years, we’ve accumulated information on branches of the Cassidy clan we cannot as yet make a definitive connection to. It’s not a lot of material and we have not published it, but we’ll be happy to at least give it a cursory look.

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