The roots of the KitchenAid dishwasher go way back to around 1886 when American inventor, Josephine Cochrane devised a dishwashing machine that used jets of water to clean dishes without moving them.  Her machine was in use and on display at 2 World's Fairs - but the machine was drawing the most interest from commercial clients in the hotel and restaurant business.  Her company became the Crescent Washing Machine Company in 1897 and was acquired by the Hobart Corporation in 1913 shortly after Cochrane's death.   Hobart improved the design, introducing a rotating spray-arm to wash dishes.  

It was not until 1949 that Hobart's KitchenAid division introduced their first home dishwasher, the KD10.  A fairly simple model with a large cast-iron spray arm (the first were white) and stainless-steel racks to hold dishes and glasses.  The machine would wash, double-rinse, and then dry the dishes with heated air blown into the wash tub.  This was the KD10 machine.   It set the standard for dishwasher design - front-loading, wash-arm spray system, dual rolling racks (and the first adjustable upper rack), and most interestingly, a 24-inch wide cabinet that was easier to integrate into a kitchen plan. 

Towards the end of the KD10 run, racks coated with rubberized cushioning were introduced.  This carried over into the all the later models.   These first models were gravity-drain, meaning serious plumbing work was required for installation.  But that was the case with just about all the home dishwashers of the day... 

KD11 was the next version of the KitchenAid home dishwasher, pretty well the same as the KD10, but now a model with a cabinet, on casters, and with a pump to drain and direct the used wash water was introduced.  The first 'portable/convertible' dishwasher was born.   The next KitchenAids in the late 50s were the KD12 series.  Again, no serious change in design but there was some restyling (a fancier door handle) and the built-in models could be had with a brushed-chrome or copper front to add some zing to a modern kitchen.  KD12's were gravity-drain models, the KD12P models had an integrated drain pump, and a new, "budget" KitchenAid KDC-P2, a top-loading mobile dishwasher was introduced.   The 11 and 12 series machines had one spray arm - a heavy cast-iron one with a blue finish. 

In 1961, KitchenAid introduced their 14 series dishwashers, with three distinct models, plus a top-loading portable.  The top-of-the-line Superba models featured a double-wash, triple rinse washing cycle.  On the Superba, there was a choice of washing cycles - Full Cycle for a complete pre-rinse/pre-wash, main wash, triple rinse, and hot-air dry cycle.  Utility And Utensil offered a pre-wash/pre-rinse, main wash, triple rinse, and short dry cycle.  The idea was that pots, pans, and utensils would not be fully scrubbed by this cycle, rather the heavier soil loosened and not allowed to dry back on too badly.  There was also a Rinse And Hold cycle for just a pre-rinse of dishes.  Cycles were selected by pushbutton and a rapid-advance timer cycled through the parts of the cycle not selected.    There was also an Imperial model with a 2-button cycle selection for Full Cycle or Rinse and Hold.  Finally, there was Custom model - it was more or less a 12-series machine:  single wash, triple rinse, and dry.  The 14 series offered models with gravity drain or pump options (the Custom models only had gravity drain - I am guessing they were intended to replace a KD10 that was getting worn out!).  The portable/convertible model made it's reapperance, but KitchenAid still offered the top-load portable version.  The 14 series was the last to use the 'Big Blue' wash arm. 

In 1965, KitchenAid introduced the 15 series dishwashers - a new washing system, the 4-way HydroSweep was featured on all their models:  Superba, Imperial, and Custom.  As with the 14 series, the Superba featured push-button cycle selection with a rapid-advance timer, however a new washing option was added.  A 'Sani Cycle' offered a final boosted-heat rinse in which the machine would fill, heat, and pause until the water reached 155 degrees.  There were still undercounter models, portable/convertible models, and the top-loading portable models - all now featured a drain pump for easier installation.

I own a KD10, KD12, KDC-P2(12-series top-load portable), KDS54 (14-series portable/convertible), KDS55 (15-series portable/convertible) and a KDC-P5 (15 series top-load portable)  so my knowledge/experience with KitchenAid dishwashers ends there.... LOL  

Dang it, that's right...  Should've checked my own archives before posting... LOL