Sadie Alexander was the first Black woman economist in the United States. This trailblazing math whiz devoted her career to challenging segregation and taking on institutions that kept Black people from advancing financially. That work included serving as the first woman secretary of the National Bar Association, fighting to desegregate the military, and serving on President Harry Truman’s Special Committee on Civil Rights. “I knew well that the only way I could get that door open was to knock it down, because I knocked all of them down,” she famously said.