The Colt Woodsman pistol is a magazine fed 22LR Caliber semi-automatic pistol that was built by Colt from 1915-1977. From 1915-1927 these pistols were known as the "Colt Automatic Target Pistol" or the "Pre-Woodsman".
There are 3 series of Woodsman pistols which correlate to 3 frame designs. The First Series refers to all those built on the S frame as it existed prior to and during WWII. The Second Series includes all versions built on the second S frame design from late 1947 until mid 1955, and Third Series means the third S frame design as used from 1955 to the end of regular production in 1977.