Purist fans of Arthur Conan Doyle's legendary detective Sherlock Holmes usually heap scorn and derision on Sherlock Holmes In Washington as it is not based in any way on one of Conan Doyle's stories. It is clearly an inferior product and I'm by no means a Holmes purist.
But this was wartime and it would only be natural that world's most famous detective be called on to lend his services overseas when a British agent carrying a vital document disappears, but not before he passes it on to an unsuspecting Marjorie Lord on a train. Holmes and Watson go to America at the behest of British Intelligence to find out just what happened.
Holmes and Watson dressed in their Victorian/Edwardian attire seem dreadfully out of place in wartime Washington, DC. Still with the keen intelligence that Holmes has and Basil Rathbone brings to the role, those enemies of democracy had no idea what they were dealing with.
As a bow to current radio favorites, Thurston Hall plays a bloviating southern senator very much along the lines of Senator Claghorn from the Fred Allen radio show. Might have been even more interesting if Kenny Delmar who originated that character had been in Sherlock Holmes In Washington. Still Thurston Hall was quite good, possibly the best thing from this film.
After some wartime propaganda films, the Basil Rathbone-Nigel Bruce Sherlock Holmes movies got back to some of Conan Doyle's stories as the material for the films. Good thing too.