Xavier Riddle travels back in time to meet heroes from the past - from Eleanor Roosevelt to Leonardo da Vinci. I am Katherine Johnson I am Gwen Ifill I am Mathew Henson We are Siegel and Shuster I am Edmonia Lewis I am Bruce Lee I am Sonia Manzano I am David Suzuki I am Esther Martinez I am Kofi Anan We are William and Caroline Herschel I am Grace Hopper I am Itzhak Perlman I am William Wigan