St. Catharine, also known as Dr. Samuel A. Mudd House, is a historic house near Waldorf, Maryland. It is a two-part frame farmhouse with a two-story, three-bay side-passage main house with a smaller two-story, two-bay wing. It features a one-story hip-roofed porch across the facade added in 1928. It was at this house where Samuel A. Mudd treated the injured John Wilkes Booth, who was fleeing justice a day after assassinatingPresidentAbraham Lincoln on April 14, 1865, following the defeat of the Confederacy in the American Civil War.