I come from a state -- Washington -- that has made a huge effort to digitize a lot of birth, marriage and death records, regardless of whether the person is living or not (okay, for the death ones, obviously not living. Or we would hope not anyway), and put it online to be freely accessible without charge. But like all of these projects, it is incomplete, particularly for the most populous county (duh). I cannot, for example, find a copy of my grandparents' presumably Skagit marriage certificate. I cannot find a copy of _my_ marriage certificate. But, you know, whatever. You get what you get.
Divorce is a common fact of life, and it's easy to think it is like BMD records. And it shares some characteristics with them. For example, mid 20th century newspapers commonly printed columns devoted to notices of who had died, who had gotten married, who had had a baby, who had asked for a divorce, who had been granted a divorce. As BMD records are acquired by higher levels of government, they are more likely to be indexed and/or digitized (or microfilmed, previously). A few places, like California, have created indexes of divorces for certain time periods and you can access these through for-pay services like ancestry.com, just like you can access social security death records, some marriage records, some birth and/or christening records, etc. You can interpolate a marriage date from census records, altho the question was asked less often than age, so if you don't get an entry for the person while married in that particular census, you're out of luck. But while census records asked for marital status and that could tell you that someone was divorced, I don't think any census ever asked a year of divorce.
In practice, at least in Washington State, if you are looking for a divorce, you're probably going to go to the County Superior Court where the plaintiff was living at the time. This court might be substantially more distant than the nearest Superior Court, but unlike marriage, you don't seem to get a choice. When you pay to file a document with the court, it's like an endowment; they seem to keep this stuff forever, altho files not "filed" may wind up in an archive somewhere else. I'm still working that angle in a couple places.
But divorce varied wildly in implementation over time. There's a Canadian database for searching for statutory divorces, which at least some sources say is the only way you could get a divorce in a certain time period -- but then later on the same web page, you find out the provincial courts handled them, too, raising a whole series of questions like, what does "divorce" mean.
What I cannot seem to find is the kind of genealogical novice resources that are fairly straightforward to find for BMD records. And to the extent I have found novice resources for finding divorces, they're not very good.
"Official divorce records: Official divorce records are those that can be accessed, usually for a fee ranging from $12 to $20, through each state's Department of Health and Vital Records." There's no reason anyone needs -- and a whole lot of laws stopping people from getting -- a certified copy. Sometimes you can get non-certified copies this way, but honestly, I've never even managed to get BMD records this way. I don't know why it's even listed as an option. Also, this is not useful for getting anything genealogically interesting, since a lot of places the divorce records are unavailable through this system anyway -- they're still kept at the county level and this is a state level process.
A little further down, it suggests this:
"State Superior Court: Check with your state's superior court, specifically the family law division or civil records department, to search for divorce records. County Superior Court: You can also research the divorce records kept in the superior court at the county level. Again, this information will typically be filed with the family law division or the civil records department. County Clerk's Office: If researching at the court level does not provide you with the appropriate divorce record, then look into the specific county clerk's office. Some states, such as Florida, organize all of their civil records in the Official Records Index, which is maintained by the county clerk. Authoritative Online Resources: Divorce records can also be easily researched and accessed through authoritative, online genealogy resources."
Again, how is this going to help? If you're doing genealogy, you're probably looking for something at least a few decades old, which means it won't be in the family law division and, odds on, outside a small number of (to be fair, populous) states, it won't be kept at the state level. I'm further flummoxed by the idea that the County Superior Court and the County Clerk's Office are treated as separate entities. In places where there's enough business for them to be separate, the divorce records you are looking for will accessed through some even more specialized entity (in my King County cases, I'm interacting with the "Correspondence Clerk" at the Superior Court).
Nowhere in this verbose discussion are newspapers mentioned at all, but most of the information I've gotten so far on divorces (outside of convenient indexes for a small number of states for a small number of years) has come from newspaper columns listing divorces asked/filed and divorces granted (or dissolution, depending on how that paper listed things). And these were _all_ newspapers online, either through the short-lived google newspaper scanning project, the New York State project (which may have been part of the google thing), the Seattle Times historical archive, genealogybank.com or newspaperarchives.com.
I'm not sure why it's hard to find here's-how-to-get-started advice on divorce and genealogy. If I keep not finding it, I may write it. Because this needs to be out there, if only so amateur family historians can start building a base of information that can be mined in the future to better understand patterns of divorce.
ETA: I looked in _The Source: A Guidebook to American [sic] Genealogy_, Edited by Loretto Dennis Szucs & Sandra Hargreaves Luebking. I mention this in some detail for several reasons. First, that "American" means "what is or became the United States as current constituted". Good luck finding anything useful on Canada in this thing. It might be there, but trying to find anything Canada-specific is ... not easy. Mexico is not better. Second, every single time I've referred to this volume, it has disappointed me. To be fair, I go here _after_ internet research has failed me, so it isn't an easy bar to meet. Third, it does have a couple of pages on divorce.
And they are about as awful as the Archives.com page. In addition to providing a very limited amount of information, some of which is a horrible mish-mash of current or recent practice and historical practice, it has a section on "Divorce Meccas" which manages to reproduce a bunch of ancient prejudice without apparent perspective. It's useful to point out that if you are absolutely sure your ancestor got divorced in a time period where That Was Not Possible, there are places you should look other than where they lived before or after. You do not need to act like the number of divorces processed in those "Meccas" was anything astonishing. Even information as simple as where-do-I-find-the-decree isn't handled well. "Most nineteenth-century and some earlier divorces will be found in county or circuit courts or their counterparts in the county where filing occurred." In most of the states I've checked so far, that practice continued _well_ into the 20th century.
The one good thing about The Source's divorce coverage is that it mentions newspapers as a source.