The first cartoon where we hear Jerry speak throughout, but only in narration form.
Due to the last scene of the short which it is implied that Tom and Jerry decided to commit suicide by waiting for a train to run them over and killing them, a Internet creepypasta was created stating that Blue Cat Blues was the final Tom and Jerry animated short.
The implied suicide in this short film has made various American TV networks hesitant to air it on TV.
Since Jerry Mouse is telling the story of Blue Cat Blues through inner monologue, the short does not break the "cardinal rule" of Tom or Jerry physically speaking in their cartoons.
Although thought to be the final short , this is simply not the case. Prime examples would be "Tot Watchers", the actual final short, was released in 58 and "Timid Tabby", was released in 1957. In a nutshell, many shorts were released after this one.