Thanks to demographic and political changes, Democratic contenders are addressing this issue for the first time.
Catholic Church records document the earliest black history in the US, going back to the 1590s. These records tell the histories of Africans, free and enslaved, who were part of Spanish expeditions.
American slaves couldn't hold property – including patents on their own inventions. But that didn't stop black Americans from innovating since the beginning of the country's history.
The slave trade was used to fund American universities. Scholars are looking to recover the lost stories of the enslaved humans who built some of America's oldest institutions.