Very little is known about the real Frederick Aiken. No photographs of him exist.
The Surratt boarding house still stands in Washington, DC's Chinatown.
The American Film Company's first film. Their mission is to make historically accurate films about America's past, though it should be noted that Mary Surratt's innocence is very dubious.
Mary Surratt's house is now a museum in what was then Surrattsville, Maryland. The U.S. Post Office renamed the town Robeysville, due to the notoriety of the Surratt name. In 1879, Robeysville was renamed Clinton.
James McAvoy only spoke with an American accent while shooting. In between shots he spoke with his normal Scottish accent. Director Robert Redford asked McAvoy if he would speak to him with an English accent, because Redford couldn't understand the Scottish one.