Ireland - McCool - Swain - Walker Autosomal DNA Research Project

We're particularly interested in our McCool and Walker ancestors because they're connected in multiple ways, because they have such fascinating histories..., and because our exact connection to them isn't completely clear. We know, however, that our families are all strongly connected by DNA evidence.

Thanks to the willingness of multiple McCool descendants to provide me with "Viewer" access to their lists of DNA matches, I've able to link our family to Swain descendants who are not also McCools. Visit the Swain Research Project to learn more.


We believe that my fifth-great grandfather, Archibald McCool, was born about 1735-1740, northwest of Belfast in what is now Northern Ireland. He and his wife had several children before emigrating to America, where the rest of their children were born. As a British citizen, he and his eldest son took up arms to defend the Empire against colonial insurgents. They both died about May 1780 during the Siege of Charleston (a major British victory).

After the war, many loyalist families had their lands confiscated by the Americans. The British offered them land in Ontario as thanks for their support during the war. Archibald's widow Catherine (maiden name probably McCall) took all of her remaining children (except one) to Ontario, in a long journey with several other families - including that of William Walker and his wife Sarah (probably McBride). Three of the McCool children married three of the Walker children in Ontario.

A generation later, two Ireland brothers married two McCool sisters in 1848 in Macon County, Illinois. Those two McCool sisters are believed to be descended from one of McCool/Walker pairings. However, the paper trail from the early 1800s is a bit murky. We hope to resolve the issue through a genealogical research project that includes both an autosomal DNA (atDNA test) and genealogical (paper trail) review.

We welcome family members to participate in the research at any level - or to simply use the information that we gather.

Family Stories

Several Ireland and McCool histories are posted on the site now. I have early Walker and McCool stories and genealogies that will be added to the site in July 2017. Story contributions from other family members are greatly appreciated: .

How You Can Help

Family members can contribute to the project by simply providing the names of their grandparents - or perhaps even privately sharing their list of DNA matches with us. We don't request personal information like names, birthdates, or location information about any living people - including DNA matches.

  1. Most needed: help us determine how you connect to the Ireland, McCool, Walker, Swain or other related lines. It's fine to skip yourself and your parents and make the connection to a grandparent level. If you don't know how you connect to us, the names and birthdates of your grandparents would be helpful; we may be able to make the connection for you.
  2. Perhaps a few people would be willing to share your list of AncestryDNA matches with us. We don't need access to anyone's actual DNA results, just read-only access to their list of AncestryDNA matches. Learn about sharing matches - and how to do it.

Contact Kevin at with information, questions or corrections.

Project Goals

  • Collect and share family stories / photos with our Ireland - McCool - Walker cousins
  • Connect as many Ireland - McCool - Walker DNA matches to our family tree as possible
  • Confirm (or identify) the parents of George McCool (1805-1866)
  • Identify the parents and ancestors of George McCool's wives: Maria L. Hazleton (1807-1835) and Elizabeth Swain (1814-1881). Locate DNA matches to their relatives.
  • Fix any errors and fill in the gaps in our mutual genealogical trees

Project Success Story

One of our Ireland cousins who'd been adopted had recently discovered his brother through DNA testing. I contacted him as part of this project, and was able to send him a great deal of information about our family history that he'd never known.

Our Ireland - McCool - Walker Line

As part of this project, I'm researching people who are DNA matches to multiple members of our McCool family. These are the McCool descendants used as the starting point for the analysis:

  • GI, GP, SI and SM are my father and his three sisters; they are DNA-confirmed full siblings. Anyone who is related to one of them is related to all of them, even if a DNA match doesn't match to all four of them.
  • JI is a second cousin to the four siblings.
  • AF is the daughter of a second cousin of both the four siblings and of JI. She is their second cousin once removed, and my third cousin.
  • I'm KI, son of GI. I inherit all of my Ireland/McCool/Walker DNA from my father, so my results don't add any information to the project.
  • CH and KB are the granddaughters of JI. I haven't requested access to their DNA results; their results wouldn't assist in this project.
  • EM is the granddaughter of John McCool, Maria's younger brother. For the first time, we have access to the match lists of someone not descended from Maria.

Here's a chart that shows how we're related:

Known McCool/Walker Relatives

All of these DNA matches are accurate. However, it's possible that we could have assigned a parent or two incorrectly in the late 1700s / very-early 1800 era. That may also be true with living people, as those relationships aren't publicly available. Part of the goal of this research project is to identify and correct such errors. Here's what we think we know:

McCool: click to Open; click again to Zoom In

Click on the image below to open it in a new browser tab. Then click on it again to zoom in to a readable level. Scroll left or right to view.

Walker: click to Open; click again to Zoom In

The Walker connections still present many questions. On the one hand, multiple DNA matches from our family to the Walkers appear very helpful. On the other, the higher-than-expected strength of several of the matches indicates that we may still be missing some key information.

Click on the image below to open it in a new browser tab. Then click on it again to zoom in to a readable level. Scroll left or right to view.


Here are some definitions that may help people interpret our charts.

  • Known: "Known" family members have a DNA match to my family AND have a genealogy trail to a shared common ancestor. When there's a combination of a DNA match and a genealogy trail, the DNA match is almost always accurate. The actual genealogical link between the two matches is still subject to error. They could be related through a different close relative other than the one noted.
  • Centimorgans (cM): a measurement of shared DNA between two matches. All of the data points in our genealogical charts are given in cM.
  • Shared Matches (icw): If two AncestryDNA matches both closely match to another person (20+ cM of shared DNA), Ancestry labels that a shared match. In some cases, they all share a common ancestor(s). Frequently though, the shared match links to each person in completely different, unrelated ways. When people from multiple lines in the same family share a match, however, that usually means they do share a common ancestor.


Based on multiple lists of DNA matches and multiple Ancestry trees, I have:

  • assembled a list of "known" Ireland, McCool and Walker matches
  • charted the amount of DNA they share with members of my family
  • noted people who are shared matches and who appear to be likely related to us through these lines

Known Ireland / McCool / Walker Matches

This chart presents a very detailed analysis of how much DNA the known Ireland, McCool and Walker matches share. The matches appear at the top of the chart, in the same order from left to right, as in the above McCool DNA tree, with Walker-only matches on the far right. Direct descendants of known matches aren't included on the top axis, but are shown on the left side of the chart. I recommend opening the Walker DNA tree and jumping back and forth between the tree and the chart to view how everyone is related.

Color Codes
  • Every known Ireland is also a McCool and a Walker - shown in shades of green and brown
  • Every known McCool is also a Walker except for one match: DP - d...psych; McCools are shown in shades of blue
  • A number of known Walker matches don't appear to be McCool descendants - shown in shades of red

One of the important things I'm trying to do is identify the number of ancestral lines that people share. My definition of a shared ancestral line is anyone who is related as a sibling, first cousin, or a descendant of the above. My father, GI, and I, along with his three sisters GP, SI and SM, represent a single ancestral line. Anyone who matches to one or more of us is considered a single line match - whether they match to one of us or all of us.

JI and AF are second cousins or more to each of us and to each other. They each count as separate lines.

The idea here is that the more lines you match to, the more likely you share a common ancestor.

Ancestor Coding

On the fourth line across the top, there are various codings that indicate the common ancestor shared by people in a family

  • WM is William McCool
  • MM1 and MM2 are two separate lines descending from Margaret McCool
  • Under HM, PG and RR are both shown because siblings often have differing matches; they are shaded together because as siblings they represent a single line. EG is not shown on the left side but not the top because EG carries a subset of RR's DNA.
  • Each number with a decimal point indicates the exact amount of DNA shared between my family members and that individual, in cMs
  • Each number "1" indicates that those two people are a "shared match" with one or more members of my family
  • Important: many of these people without a "1" match each other - but they aren't close enough matches to my family for me to know if they do
Click to Open; click again to Zoom In:

Possible Ireland / McCool / Walker Matches

The people included on this chart match to my family plus multiple lines of our known related families. That means there's a strong likelihood that we share common ancestors in the Ireland, McCool, Swain or Walker families - or perhaps even ancestors further back in time.

If your Ancestry username is on this chart, please tell us how you're related to us (if known). You don't need to provide your name or personal information about any living people. We can attach you to the tree anonymously if you provide the names of your connecting grandparents. If you don't know how you connect to us, I'd be very happy to help you research that. Please email me at .

Chart Axes

The top axis shows the known Ireland, McCool and Walker DNA matches. The left side axis lists people who match to my family and also are shared matches to multiple known family lines. In most cases, they share common ancestors with us in these lines.

Click to Open; click again to Zoom In:
Background Info about Shared Matches

There are many more people match to just two of our family lines. They could be McCool or Walker descendants. Often, though, the match may just happen to have two ancestors each related to one of our lines - but not through a shared ancestor. They're not included in these charts - but we'd love to hear from anyone related to our families.

Here's an example:

  • The Hight family has strong historical roots in Virginia. Two Hights married children of George McCool. All of their descendants will match both to the McCool family and to Hight descendants unrelated to a McCool.
  • My father and his three sisters are McCool descendants, but his mother is not. Her historic ancestral lines are widespread across the South, including Virginia.
  • It's very possible that a Hight descendant who is not a McCool descendant would also have an ancestor who is related to my non-McCool grandmother. This individual would be a match to the Hight-McCool descendants and also a match to my father and his sisters - even though the individual is not a McCool descendant at all.
  • They would show up in the "Shared Matches" list to all parties - even though they're related in completely different ways.

Privacy Policy

  • Full names of living people (other than our own) are never shared publicly - nor are full dates of birth, places of birth, or places of residence.

Are we related?

Here are the GEDmatch Kit #s for my father and mother:

GI: A909282
CL: A216073

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Interesting Links

Grandma Ireland's 100th Birthday