I did _not_ know growing up that my great-grandfather on the other side of my family had also been married four times, much less that he was divorced twice (he outlived two of the women). Discovering his marriages was a little more distant an experience, since I never met him, at least not that I recall.
Over time, I had built up enough information on the timelines of both their lives to identify the probable location for the divorce, and a probable period of years during which the divorce might have occurred. In the case of one of my great-grandfather's divorces, I had a filing announcement in a newspaper; I eventually found something similar for one of my grandmother's divorces.
The next step was to contact the court and/or archives for these times and places. I have a researcher who will be checking the Manitoba archives for my grandmother's first divorce; that's where the records from the Provincial Court would have ended up. I initially contacted the wrong County Superior Court for the second marriage. When nothing turned up, I thought about it for a while, and realized they had to go to their county seat, not the nearest county seat, and contacted the right court, which then told me they didn't have it either. But by then, I had the newspaper reference and they found it on a second attempt. The Superior Court for the third divorce has gotten back to me, but mostly to let me know they are somewhat backed up but will get to it.
Meanwhile, on the great-grandfather's divorces, King County's Superior Court Correspondence Clerk told me what to send them: an SASE and a money order for the research fee since I didn't have the case number. A branch of the state archives is also searching for the case files associated with those cases. Everyone has communicated that they are working on it.
What I have now is the second divorce for my grandmother. In Washington state, these are public records, and there's no wait-50+-years to get them (I Love Washington). I've read the filed documents (the initial filing, service, interlocutory decree and final decree, IIRC) and everyone named in it is dead; children are referred to as "children", rather than by number, age or name, thus saving me the trouble of redacting the names of those children who are still alive. The cause given is a hybrid of cruelty and abandonment and the result was a judgment in default as my grandmother was served but never appeared (and there's no reason she should have appeared; it would in no way have changed the outcome, which she wanted to be free to marry that third time). The explanation of the fault is almost exactly what I heard growing up: the second husband couldn't get along with the kids, altho when he's the plaintiff, it's a dispute about discipline.
So I've attached it to both people in my tree. I see no ethical or legal reason not to, and it seems to be an item of at least mild interest.
The biggest discovery in this part of the process is that I found the man in the 1940 census prior to marrying my grandmother. That plus another newspaper entry tells me he was _married before_, which I did not know, and had kids from that marriage, but they weren't around when my grandmother married him. The county clerk was unable to find that divorce for me, which means I've replaced one puzzle with another one.
I will also note that the county court which gave me the copy of the decree gave me the choice of hardcopy or emailed pdf; I chose the latter. Payment was through The Official Payments Corporation (no, I did not make this up), with a $1 service charge. I went to the bother of setting up an account with them, because I'm betting I'll be giving them money in the future. No SASE and money order for this very rural county in eastern Washington.