The grove of trees that Joan Bennett runs through when she flees the house is the same grove that the Wolf Man ran through in the 1941 film, also made by Universal. In particular, the tree she leans against is the same one that the Wolf Man is beaten under.
Fritz Lang's attempt to do his version of Rebecca (1940) was a project fraught with disaster. It ran over budget and over schedule, while Lang was at constant loggerheads with his leading lady, Joan Bennett. The first preview of the film attracted comments like "beyond human endurance" and "it stinks". Bennett herself referred to the film as "an unqualified disaster".
In the tour of the three rooms, Mark Lamphere recounts the tales of three murders, all of which are fictional. However in the first room, he mentions the St Bartholomew's Day massacre and the Guise family in France. The massacre is a real historical event, where French Roman Catholics attacked French Huguenots (Protestants) on 24th of August 1572 resulting in many deaths. The Guise family was a leading family in the Roman Catholic faction and may have been involved in the instigation of the unrest and other actions which led to the massacre.