Here's a quote from another article about their history.
The German Shorthaired Pointer combined in field-dog requirements those qualities which have long popularized the various breeds of hunting dogs. Through judicious crossing of the descendants of the old Spanish Pointer, English Foxhound, and local German tracking hounds, the breed has acquired a keen scenting power linked with high intelligence, leading to its reputation as an ideal all-purpose dog. The breed is proficient with many different types of game and sport, including trailing, retrieving, and pointing pheasant, quail, grouse, waterfowl, coons, possum, and even deer.
The origin of the German Shorthaired Pointer, as with most breeds, is not clear, but the source of basic foundation stock seems to have been the German Bird Dog, related to the old Spanish Pointer, and various crossings with local German scent hounds and track and trail dogs (Schweisshunde). When the Germans finally introduced the fine English Pointers to lend elegance to the German Shorthaired Pointer prototype, the result was a magnificent utility dog that combined sporting virtue with clean lines, good looks, sound temperament and longevity. The German Shorthaired Pointer was first admitted to the AKC Stud Book in 1930, with the first specialty and field trial sponsored by the parent club held in the same year, 1941.