One of the nice things about teaching literature that's not from the 21st century is that students get to have a window on the past and to think about things that they might not have thought about before. There are two areas or subjects, though, that they seem especially fascinated by: race relations and sexual mores.
Because we still (sadly) live in a racist culture, they "get" the racism of the earlier texts pretty well, although they bridle at the unfairness of racist practices and are angry at the laws reinforcing them. The whole white panic over "mixed blood," and the pseudoscience that supported theories of race in the 19th and early 20th centuries, seem to them so deluded as to seem incredible to any rational person--which it is, of course, even though we have to understand those attitudes in order to understand points in the plots.
The harder sell, I think, is the issue of sexual mores. Just think about the books in which either reputed sexual waywardness (by 19th-century standards) or evidence in the form of the unmarried mother appear:
Pride and Prejudice
The Scarlet Letter
Tess of the d'Urbervilles
Jude the Obscure
The House of Mirth
(I know there are more--commenters?)
The difficulty lies in trying to get them to see what a huge deal it was to be pregnant and unmarried in those days, and the amount of scandal that it would have brought not only to the woman but to her family. Even if she married the man who had impregnated her, she'd be at the very least a topic for gossip--and a target of barbs from malicious family members who refused to go along with the polite fiction that the baby was "premature" if born less than 9 months after the wedding. Other possibilities, if marriage wasn't an option, included abortion (illegal), being sent away to live with relatives or put into a home, putting the baby up for adoption, or even having the baby and then having the family pretend that the grandmother was actually the mother.
Students are problem-solvers, and even after they understand that unmarried pregnancy is a problem, they have a lot of questions:
"Why can't she just go and get a job somewhere?" Respectable employers aren't going to hire an unmarried woman with a baby, so she'll have to pretend to be a widow and risk being found out. Also, there's no day care, and "baby-farming" means the death of the child, pretty much.
"Can't she go back to her family?" She can--Tess does, for example--but a lot of families considered the disgrace too great.
"What if the man marries her?" Too late--the stigma is already there, except perhaps in a farming community like the one Antonia lives in, and Antonia doesn't marry the father of her child.
The really heartening part of this exercise is that they genuinely don't see what the big deal is about this issue. What that says to me is that huge portions of that whole pernicious culture of shame and secrecy and having one's life ruined over this issue are just not part of their vocabulary, even if they joke about the "walk of shame." But to get them to understand the literature and the importance that the characters place on their sexual situations, I have to put them back in that culture momentarily. I have to get them to unleash their inner Puritan.*
*Yes, I know: a lot of Puritan brides were pregnant before marriage, but you know what I mean.