Cochrane was unhappy that her servants kept chipping her best china so started washing the dishes herself. Unhappy with having to do such a thing, she set about designing a machine that could do the job instead.
Following the death of her husband in 1883, Cochrane was left with debts and the dishwasher became a potential source of income. She patented her invention in 1886.
In 1893, Cochrane's Dishwasher won the prize for "best mechanical construction, durability and adaptation to its line of work" at the the Chicago World's Fair.
More on Josephine Cochrane can be found here.