That might be true, but those articles are using a restaurant employees advocacy group as their only source. And beyond that one person's conjecture, there isn't much evidence that it's actually true.

I agree. If tipping really came to prominence during that time period, I wouldn't at all be surprised if it had a racist history. But given that no one at the time hid their racism, I'm surprised that neither article could manage to make a clear connection.

I found a Time article agreeing, but upon further investigation it cites the exact same advocacy group as their source as well. I'll agree with plausible but dubious.

I'm pretty opposed to tipping as a practice, or at least the reduced minimum wage for tipped positions, but I was expecting more from those articles. If you strip away the appeals to identity politics they are much less interesting or compelling. The WP article basically goes away save for a handful of cherrypicked sources. The Time article retains some vague handwaving about how many restaurant workers were former slaves around the time tipping caught on--how do they fail to draw a clear connection to racism in a time when overt racism was a point of pride?