Our Campbell family begins with Cornelius Campbell and Anne Hayden, whose ten children were born and raised in Dundas Co., Ontario, near the St. Lawrence River. I'm assuming they met and married in Canada since all their kids were born there. Daughter Margaret married Edward Donnelly and began our branch of the family in western Missouri. Half of the Canadian Campbell kids moved to Denver, Colorado after the death of Cornelius. Perhaps also after the death of Anne, but I don't know when that was. Oldest son Thomas remained in Dundas co. where he married, raised a family and lived his entire life. One of his kids, Leonard, made his way across the river to Ogdensburg, New York, bringing more Campbell relatives into the US. My grandfather and his sisters used to go back and visit their Donnelly and Campbell cousins from time to time, but as far as I know we are not in touch with any from this area anymore. Some of the kids never married. A few I just have no record of. The only other branch with kids that I know of are the descendants of Joseph Campbell and Mary Mackey, married in the Denver area in 1883. My mom and her sisters have been in touch with one of Joseph's grandchildren; they're all 2nd cousins.
While poking around the information our Campbell cousin passed on to me about the Denver Campbells, I found a link to lots more information about some related descendants that's been posted on Rootsweb. It starts here with John Campbell, Joseph's oldest son, and his wife, Ellen Solis.