Here we have it. The guitar features a Dreadnought body. I'm led to believe that Martin was the first guitar manufacturer to use this style of body, which was readily copied by everybody else and is now almost ubiquitous as the body shape of guitars.
My favorite parts include the cutaway to allow better access to frets higher than the 12th (which I didn't realize I would want to do so much when I bought my first guitar) and the inlay dots on the fingerboard that are much more low key than what you usually see.
Oh yeah, and the headstock says "C.F. Martin & Co".