The first commercially available power-moded dishwasher was invented by Josephine Cochrane in 1886.
More Info: Dishwashers are one of the most common home appliances; however, many people do not know how these amazing machines transformed. The history of the dishwasher is actually quite lengthy. Starting out as a simple box that splashed water and growing to the technologically advanced machines we now own, the dishwasher has passed through many developmental stages over the years.
The first dishwasher was invented in 1850 by Joel Houghton. The machine was wooden and had a hand-turned wheel. The wheel simply splashed water over the dishes in the machine. It was not really a working machine, but it was the first dishwasher to have a patent. After the introduction of this dishwasher, advances began coming quickly. L.A. Alexander patented a device in 1865. This machine also used a hand-crank, which was used to spin a rack of dishes through splashing water. Again, this did not do much to clean the dishes, but it was advancement. However, these machines were manually operated and not practical. 
The Automatic Dishwasher
Only a few years later, in 1886, Josephine Cochrane developed a machine herself. Her dishwasher had specially designed racks to hold plates, saucers and cups. A motor was used to turn the wheel and a boiler was attached to the machine. This allowed hot water to spray over the dishes, which was far more effective that earlier models. Her design gained a lot of recognition and she began her own company, which is now known as KitchenAid. This was the birth of the automatic dishwasher. 
The 1920s and Beyond
In the early 1920s, dishwashers began to include permanent plumbing. In 1924, William Howard Livens received a patent for modifications that were very similar to the machines used today. It had a front door used for loading, a rotating sprayer and wire racks. In 1940, electric elements used for drying the dishes were implemented into the design. 
From the 1940s on, the dishwasher maintained its basic construction, with small additions being added. By the 1970s, it was one of the most common home appliances. The machine became cheaper to buy, allowing more homes to install one. It was a blessing to many women who used to be burdened with the chore of washing dishes by hand. Today, two-thirds of homes have a dishwasher. 
 Gref, Lynn G.. “Inventions of the Rise.” The rise and fall of American technology. New York: Algora
Pub., 2010. 75-76. Print.
(Note) The evolution of inventions often results in multiple inventors being credited with their origination.
Some people believe the first person to receive a patent is the true inventor. In the case of the specific
question of ‘who invented the dishwasher’, if simply reworded to ‘who invented the first practical and
commercially successful dishwasher, the answer is unquestionably Josephine Cochrane.
In his book, The Rise and Fall of American Technology, Dr. Lynn G. Gref argues that the invention of the
dishwasher should be credited to the woman who invented the unit that we still recognize today. Dr.
Lynn G. Gref’s 40 year career as a developer, manager and consultant in research and development
applied to defense, space and intelligence needs, as well as his current position on the Board of Advisers
of the College of Natural and Agricultural Sciences, University of California, Riverside, gives him an inside
perspective on the evolution of American technology and exactly whom should be credited with inventing
the dishwasher. Gref argues that though Houghton and Alexander received patents for their inventions,
they did little more than splash water on the dishes and were not at all practical. He further argues that
it is clearly Josephine Cochrane who should be credited with the invention that we now consider the
modern dishwasher. Quoting Gref, “it took a woman to invent a practical dishwasher”.
 “Improvements in apparatus for washing household crockery and the like .” ESpacenet Patent Search. N.p., n.d. Web. 25 Sept. 2014. <http://worldwide.espacenet.com/publicationDetails/biblio?CC=FR&NR=579765&KC=&FT=E&locale=en_EP>.
(Note) Dated October 23, 1924, this source has posted a copy of the original patent extended to William Howard Livens. The abstract outlines the principle upgrades proposed to the appliance including the primary alteration of connecting the appliance to the permanent household water supply allowing both hot and cold water to enter the unit.
 US Department of Housing and Urban Development
HUD RELEASES 2009 AMERICAN HOUSING SURVEY
(Note) The estimated two-thirds of homes that have a dishwasher is a median average. Newer units are more likely to have these appliances and income level factors in heavily. According to the Department of Energy, the dishwasher is one of the few major appliances that are not found in all households equally, but are more prevalent in homes in a higher income bracket. While only 18% of homes with a household income of $15,000 are equipped with a dishwasher, 83% of homes with an income greater than $75,000 own one. http://www.eia.gov/emeu/recs/appliances/appliances.html
“No. 1476 Inventing the Dishwasher .” University of Houston. N.p., n.d. Web. 6 May 2010. http://www.uh.edu/engines/epi1476.htm.
Bobolicu, Georgiana. “History of Dishwashers – How dishwashers came into our homes – Softpedia.” Gadgets Area – Softpedia. N.p., n.d. Web. 24 Mar. 2010. http://gadgets.softpedia.com/news/History-of-Dishwashers-033-01.html.
“How dishwasher is made – manufacture, history, used, parts, components, structure, steps, product, machine, History, Raw Materials, Design, The Manufacturing Process of dishwasher, Quality Control.” How Products Are Made. N.p., n.d. Web. 24 Mar. 2010. http://www.madehow.com/Volume-6/Dishwasher.html.