York was William Clark’s slave. According to historical documents, he was large and athletic. He played an integral role in the Lewis and Clark expedition, once saving Clark’s life, yet he is largely absent from accounts of that famous journey. In fact, York is hardly known at all in contemporary public memory. His conspicuous absence marks an intersection between history, race, and ethnicity, signals the legacies of slavery that still plague American culture, and underscores the politics of public memory. Like so many other African Americans, York is an invisible hero in American history. His absence is an elegant metaphor for what is at stake in remembrance.