In , Sherlock, Jr. was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant," and on 14 June the American Film Institute, as part of its AFI 100 Years... series, ranked the film as #62 in the list of the funniest films of all time (AFI's 100 Years... 100 Laughs).
One day he is accused of stealing his girlfriend's father's watch. He falls asleep on the job and dreams that he is a Sherlock Holmes-type detective, solving the case of who really stole the watch.
Into the film: Keaton "walked" into the movie via the power of suggestion. The scene shifted back and forth several times from the projectionist's booth to the movie that was being shown. But for the last shift, instead of showing the movie, the camera this time showed a stage with live actors, designed to replicate the look of the movie. Therefore, Buster actually climbed onstage, but created the illusion of joining the movie.
Revealing the trick: During the scene following his "entry" into the movie he's projecting, the scenery around him changes abruptly several times. It wasn't until the 1940s that Keaton revealed that he and his cameraman had used surveyor's instruments to position him, and the camera, at exactly the correct distances and positions to provide the illusion of continuity.
"The impeccable comedian directs himself in an impeccable silent comedy...Is this, as some critics have argued, an example of primitive American surrealism? Sure. But let's not get fancy about it. It is more significantly, a great example of American minimalism—simple objects and movement manipulated in casually complex ways to generate a steadily rising gale of laughter. The whole thing is only 45 minutes long, not a second of which is wasted. In an age when most comedies are all windup and no punch, this is the most treasurable of virtues.
Film critic Dennis Schwartz wrote,
"[The film is] one of Buster's superior silent comedies that's noted for his usual deadpan humor, frolicsome slapstick, the number of very funny sight gags, the many innovative technical accomplishments and that he did his own stunts (including the dangerous one where he was hanging off of a ladder connected to a huge water basin as the water poured out and washed him onto the railroad track, fracturing his neck nearly to the point of breaking it. Keaton suffered from severe migraines for years after making this movie).
The review aggregator Rotten Tomatoes reported that 100% of critics gave the film a positive review, based on 14 reviews, marking the film as "Fresh.