Heather Cox Richardson (born October 8, 1962) is an American historian who works as a professor of history at Boston College, where she teaches courses on the American Civil War, the Reconstruction Era, the American West, and the Plains Indians. She previously taught history at MIT and the University of Massachusetts Amherst. Richardson has authored seven books on history and politics. In 2019, she started publishing Letters from an American, a nightly newsletter that chronicles current events in the larger context of American history. Richardson focuses on the health of American democracy. As of July 2025, the newsletter had over 2.6 million subscribers, making it one of the most popular Substack publications.