A memo was placed in the authority file for the coat:

I have this day removed from exhibit the Lincoln coat...alleged to have been worn by Abraham Lincoln on the night of his assassination. I have caused this removal to be made because I am convinced that these articles of clothing could not have been worn by Lincoln when he was assassinated. I have seen the evidence relating to the suit, great coat, and other articles of clothing now in the possession of the [Donn] family, which must convince any fair minded person that this clothing, rather than that owned by the Chicago Historical Society, was the clothing worn by Lincoln on the night of April 14, 1865.

The Lincoln collection on display in the Chicago Historical Society's galleries, c. 1940.

Paul Angle, noted Lincoln scholar and director of the Chicago Historical Society, investigated the Donn suit in 1936 and 1949. Following his second examination, he removed the Forbes/Pendel coat from display.

There is no doubt that the Donn garments belonged to Lincoln, as confirmed by Mary Lincoln's letters. Whether the frock coat was worn to Ford's Theatre is open to question, however, since both shoulders are intact. Charles Leale, the first physician to reach Lincoln, ordered the coat and shirt cut off his left shoulder to search for a wound. Charles Sabin Taft, a second physician in the box seat, confirmed that Leale "had caused the coat and waistcoat to be cut off in searching for the wound." (TAFT)

The Donn frock coat attributed to Abraham Lincoln's assassination, courtesy of Ford's Theatre National Historic Site, Washington, D.C.

The Donn clothing was finally purchased in 1968 for $25,000 and presented to the National Park Service for display at the newly restored Ford's Theatre.
Mary Lincoln may have given both Forbes and Donn items associated with her husband's assassination.
The left shoulder of the Donn overcoat is missing; the left shoulder of the Forbes/Pendel frock coat has also been cut away. It is possible that Mary sent her husband's intact second inaugural suit to Donn and painter Matthew Wilson together with the assassination overcoat. The damaged frock coat would have been unsightly and difficult to wear -- it may indeed have been given to Forbes with the injunction to "never let her see [it] again." The reliability of Forbes' testimony and his relationship with Pendel raise significant questions. The associations between Pendel and Donn are also curious. Further research is necessary to determine which frock coat Lincoln wore on the night of the assassination.
Missing areas on the Donn overcoat (left) and Pendel/Forbes frock coat (right) have been outlined in red. Illustrations courtesy of Fredi Leaf and the Ford's Theatre National Historic Site, Washington, D.C.