Thanks so much for your help! I did some digging into the suggestions you made, and I feel very confident that you have the correct person. I was able to make some pretty good progress on fleshing out these histories.
It seems that the wife and the father in law were a second wife that's not the mother of the children. I'm looking for the mother's death record now.
Also, thanks for all of the help on the Hack tree. I was able to connect that to my grandmother's mother's lineage.