As the main author of the megapost (and someone who writes about the history of education), I'm happy to answer any follow up questions you might have about the history in the post. One thing I want to highlight from the post that might be helpful for understanding the context is that ingesting an abortifacient prior to the quickening (the first time a pregnant person feels the fetus move - typically around 4 to 5 months) wasn't viewed as an abortion as we think of it today. Even when early laws were passed in the 1820s related to abortifacients, the focus was on the dangerous snake oils created by apothecaries and physicians, not on the abortion itself.

Have you checked out the Abortion Megathread (that sounds awful) over here: https://www.reddit.com/r/AskHistorians/comments/uhh2j1/megathread_abortion_in_america/

Seems to line up some with what Slate is saying.