Memorial Day’s African American Origins, Argentina’s Black History, and a Hidden Figure of Horse Racing

Catch up on the race and racism news you might have missed this week.

A color photo shows a row of white marble military-style headstones, each decorated with a miniature U.S. flag sticking out of the ground in front of it.

We’re in the middle of graduation season — praise and congratulations for all those who have completed their high school, college, or advanced degrees! But even if school is out, there’s still so much interesting race and…