Your own ignorance of the law and unawareness of what constituted consent at the time does not reflect on the state of society at the time. It was always illega

Your own ignorance of the law and unawareness of what constituted consent at the time does not reflect on the state of society at the time. It was always illegal and immoral to have sex with someone who was very drunk (at least, well before either of us was born). The line was and is not always clear, but there have always been clear cases (e.g. having sex with someone who has passed out or drugged is obviously illegal and immoral). Similarly, legal contracts require a meeting of the minds, which requires that parties not be intoxicated. A quick search suggests such contracts are not void by default but are voidable.