1942 Martin D-18

Along with its Rosewood counterpart, the D-28, the Martin D-18 stands as one of the true original dreadnoughts introduced by Martin in 1932. The D-18 made a switch from a 12-fret to a 14-fret instrument in 1934 and has stayed largely the same since, with just the occasional change in wood source or cosmetic detail. Since the D-18 uses Mahogany instead of Rosewood, it is thought to have a somewhat crisper sound with more definition the top-end. 

Years of Production: 1932 - present

Specific to this Era:  Martin switches from scalloped to heavier non-scalloped bracing in 1945. 

Body Style: Dreadnought 

Wood Composition:  Mahogany back and sides, Adirondack Spruce top, one-piece mahogany neck

Notable Players:  Elvis Presley, Doc Watson, Clarence White, Andy Griffith, David Crosby