While researching Packy Dillon, I was convinced that I had identified Dillon in the 1880 census. You can find my reasoning in this post. One of the main reasons that I believed Patrick Dillon to be the son of James and Ellen Dillon, besides the fact that they had a son named John and they were of the appropriate age, was that both the Patrick Dillon family and the James Dillon family were listed next to each other in the 1880 census. I assumed that this implied a family relationship.
The interesting thing is that I probably have the right guy but I got the family wrong. Based on an e-mail conversation with Peter Morris and Jason Christopherson, it is almost certain that the Patrick Dillon in the 1880 census is Packy Dillon. However, it's just as certain that this Dillon is the son of John and Alicia Dillon, not James and Ellen Dillon.
In the 1860 census, there is an entry for a James Dillon, a 36 year old butcher who was born in Ireland and living in St. Louis. James was married to the 26 year old Alicia Dillon, who was also born in Ireland, and the two had six children: Stephen (already living on his own in 1860), Edward (age 17), James (12), John (10), Patrick H. (8), and Mary E. (2). I had seen this entry in the census and believed that this Patrick Dillon was the second best candidate after the 1880 census Dillon. It turns out that they're the same person. Patrick H. Dillon is the Patrick Dillon of the 1880 census. Patrick H. Dillon is almost certainly Packy Dillon of the Reds.
Patrick H. Dillon died in July of 1902 and is buried at Calvary Cemetery in St. Louis. In the same cemetery lot is James Dillon, Edward Dillon, Mary Dillon Clark, and Alicia Mullen. This is the Dillon family from the 1860 census. Alicia Dillon remarried after the death of James and her second husband, Alexander Mullen, is buried in the lot. Also burried in the lot are two children who died in November of 1877 and are listed as "twins of Patrick Dillon".
Peter Morris found a death record for the twins in the Missouri Archives that list the twins as the children of Patrick and Martha Dillon. The twins prove that Patrick Dillon of the 1880 census is Patrick H. Dillon of the 1860 census. It also proves that Packy Dillon most likely died in St. Louis in 1902 and not in Guelph, Ontario in 1890. Jason's research leads one to conclude that the baseball playing Dillon who died in Guelph was Andrew Dillon not Packy Dillon. Both were catchers of an approximate age and their information was most likely confused when the Baseball Encyclopedia was put together.
One of the keys linking Patrick H. Dillon to Packy Dillon is Patrick H.'s wife Martha F. Dillon. In the 1880 census, Martha F. is listed as having been born in Ohio. It's known that Dillon was in the Cincinatti area in 1875, playing for the Covington Stars. In the death notice of one of her children, Martha's maiden name is listed as Baggot and in the 1860 census Martha Baggot, age 1, is living in Cincinnati with her family. On the Civil War pension card of Martha Baggot's father, Francis Baggot, a Martha F. Dillon is listed. So it seems that Patrick Dillon met Martha while playing with Covington, won her hand, and took her home to St. Louis.
Patrick and Martha Dillon were married in 1876 and had six children: the twins who died in 1877, Edward (born around 1880), Loyola (@ 1885), Marie (@1886), and Jerome (@1888). Patrick, along with his brothers, was working as a butcher until around 1879. After that he was a vegetable peddler at least through the late 1880. After that his occupation is unknown. Peter believes that Dillon gave up baseball after the birth of the twins in 1877.
Martha Dillon lived a long life, passing away sometime in 1931 or 1932. She and her children lived on a farm on Lemay Ferry Road in St. Louis. She's listed as a farmer as early as 1909 so it's possible that Patrick Dillon bought a farm sometime in the late 1880's or early 1890's.
After seeing the records from Calvary Cemetary, the census data on Martha Baggot Dillon, and the death record of the Dillon twins, I have no doubt that Patrick H. Dillon is Packy Dillon.
I'd like to thank both Peter Morris and Jason Christopherson for their time, effort, and help. They both unselfishly shared their research on Packy Dillon with me and I very much appreciate it.