I don't think beating a woman was ever considered acceptable in America. But slapping a woman became socially unacceptable in America sometime around the end of the 1950's. Prior to that, there's no question it wasn't as taboo as it is today. Heck, there's even an infamous I Love Lucy show where the plot was Lucy thought her husband Ricky was going to slap her when he got home for something she'd done, so she tried to get a suntan so people couldn't see the impending slap mark. That plot was considered funny back then, but today Americans would be outraged.