(I'm being non-specific about the time period and location because I suspect that there isn't that much literature on this question as a whole, so narrowing it down even more might make it difficult to receive answers - however, if I have to narrow it down, I'd be interested in on the one hand early-mid 20th century America, and on the other hand say classical or medieval Europe.)
Given that there are some things which aren't criminalized but are still considered socially unacceptable, aka defending Nazism in the United States, I was wondering if we know about whether forcibly compelling your spouse to have sex with you was actually considered acceptable behavior before the late 20th century (of course, I'm sure this varied by culture, etc., but I'd be interested in whatever information for whatever culture does exist).
For example; if a (representational of the society) man is at a bar with his friends and they are talking about their marriages' sex lives, and then he says "my wife didn't want to sleep with me yesterday but joke's on her, I just forced her to!", would that be considered bizarre behavior?
I'd find it especially weird if countries where other forms of spousal violence were already generally looked down upon (aka American in the 1970s) strangely thought that something likely far more harmful than most levels of physical violence was OK.
This is specifically for places where marital rape wasn't recognized as a crime, not for the rare pre-late 20th century legal systems where it was.
Though it was not criminalized in most countries prior to the late 20th century, how socially acceptable would marital rape have been?
tl;dr:
Marital rape actually wasn't fully criminalized in the US until 1993 and there are still many exceptions and loopholes for sexual violence in the context of marriage on the books today. Historically, it was probably socially acceptable on the large-scale until the mid-80s... but there is evidence from TODAY to show that many people do not see marital rape as "real rape."
Edited to also add: Because this post is about the historical view of rape and because rape has, historically, been legally and socially constructed as a crime with a male offender and a female victim, especially in the context of marriage, this reply focuses on female victims and male offenders.
#Part 1 of 2
First and foremost, I'd like to speak to this first thing you wrote:
I'm being non-specific about the time period and location because I suspect that there isn't that much literature on this question as a whole [...]
Well, actually, there is a substantial amount of literature on this!! In fact, that literature is housed within my entire area of expertise. I'm a criminologist "on paper" (as in, that's what my Ph.D. is in), but my area of expertise is actually victimology - the study of crime victims (where most criminologists traditionally study offenders). As to your question, you said if you had to narrow it down, you'd choose betwen early/mid-1900s America or classical/medieval Europe. My area of expertise is more specific to America, but the roots of our criminal justice system and the roots of our perceptions/philosophies of "crime" and what is or is not considered crime come from our "parents" (i.e. Europe). As such, I'll give you a tiny bit of the historical European context for this, but I am by NO means an expert on European criminology, so someone else is more than welcome to weigh in on that, or fill in any gaps.
Now that that's out of the way... before I answer your question directly, I'll say this: the concept of "crime" or what is or is not "crime" is socially constructed. Further, the socially-constructed meaning of "crime" is contextual with time and place. You wrote:
I was wondering if we know about whether forcibly compelling your spouse to have sex with you was actually considered acceptable behavior before the late 20th century [...].
The language that we use to describe certain behaviors is part of how we construct the meaning of "crime." As such, you are using 2021 language to understand something from the 1900s - that is to say, you are using a 2021 construct to try to reconstruct the reality of the 1900s. The words "forcibly compelling your spouse to have sex" reflect your current reality - not even the current societal reality (which I'll get to in a moment), but your current reality, which is that it is possible to force someone to have sex with you (and that would be bad/rape), or that your spouse should have a choice whether to have sex with you. In other words, the way you have constructed your question leads me to believe that you believe that forcing your spouse to have sex with you even when the spouse wouldn't want to is:
And further, it leads me to believe that you believe that it is actually possible for a spouse to not want to have sex with their partner from time to time.
For what it's worth, I agree with you (duh). The reason I'm outlining the implications of your question in this way is that the social reality at the time of the early/mid-1900s in America did not reflect those clauses I outlined above.
Sexual intercourse within the confines of marriage did not always carry the same meaning that it does today. Today, many Americans believe that sex is done for pleasure, and it should involve two consenting adults who are capable of giving consent. Thus, we construct our laws around that belief - that to do anything other than this is a crime.
The social reality of America in the early/mid-1900s did not match the social reality of America in 2021. Generally speaking, it was just your job as a wife to have sex with your husband.
This belief is a hand-me-down from an old English doctrine called coverture (Stretton & Kesselring, 2013). Many people are aware of coverture without realizing it. For instance, in the Middle Ages, wives were considered property of their husbands. As such, when women experienced harm - for instance, if someone murdered a woman - it wasn't considered "murder," it was considered a property crime (see also Garay, 1979, PDF link). The English weren't the first to have this idea. It's something that goes all the way back to the very first set of written laws, the Code of Hammurabi. Under the Code of Hammurabi, [edit: see /u/PhiloSpo 's comment below for clarification on this] rape of women was property crime against a man - either her father, if she was a virgin, or her husband, if she was married. Note that the assumption is that she wasn't a virgin if she was married! This article includes a truly fascinating history of rape laws in the United States that really gets at the core of your question, so I really encourage you to read it.