To his contemporaries in Gilded Age Manhattan, Guillermo Eliseo was a fantastically wealthy Mexican banker and broker, with an apartment on Central Park West and an office on Wall Street. He began life, however, as William Ellis, an enslaved African American in south Texas. Columbia University historian Karl Jacoby and members of Ellis’s family from Mexico and the U.S. discuss the meanings of Ellis’s strange career and the complicated path he charted through the archives and through family memories on both sides of the border.