If you could go back in time ... what would you change?

The question came up when I making conversation with an older Black man at the Smithsonian's National Museum of African American History and Culture (NMAAHC) information desk. I cited I wanted to go back to the 2016 election. He quickly chimed in he would go back to 1452 when Pope Nicholas V wrote Dum Diversas (meaning "while different" in Latin) to subjugate and legalize slavery in Portugal of all non-Christians ("while different"), and his 1455 amended policy to legalize slavery based on skin color. His justification was to spread Christianity, which doesn't hold water with the 1455 amendment taking out the "loophole" that even if they convert to Christianity they are still slaves.

That's something you won't even find in the museum. The closest I saw was that slavery existed before 1400, but it was a short-term (for example to pay off a debt). Trading of goods had taken places. In 1452 humans became a commodity, specifically humans from West Africa who were reclassified as "slaves" (i.e., non-humans).

When I said, I don't understand how anyone could justify this. He said without hate it was "greed, it's that simple." 

This law created before Christopher Columbus "discovered" American is the root of our systems of inequality.

I recently heard the expression (unrelated to this discussion), it would be as hard as removing a drop of food coloring placed in a glass of water to fix this mess.

Other than changing the course of history with regards to slavery, what would you go back in time to change?

My next non-political thought was for Jonathan Larson to received medical treatment for his undiagnosed Marfan's disease which caused aortic dissection. A completely treatable disease had he gone to the doctor. One reason he did not was because he did not have health insurance. Something else that needs fixing in this country.