> For co-workers not familiar with the history of slavery in the United States, there is always a pause, and then some confusion about the changes. After explaining the historical context, 99% of people reply: "Oh, I understand. Thank you to explain."

Most people answer like this when they realize you are an unreasonable person who refuse to listen. Happens all the time, like "Oh, I understand (you are one of those). Thank you for explaining!", and remember that they need to stop using this word when working with you.