How important was Henry Ford to the economic prosperity of the USA in the 1920s? Explain your answer.

Yes
Ford's Model T was central to the success of American economy in the 1920s; one in five owned a car by 1929; employed over half a million workers; stimulated other industries such as road building, construction, oil, rubber, glass and leather; increased tourism - motels and restaurants; growth of suburbs; increased ability to travel for leisure activities - cinema, sports, nightlife; assembly-line production method copied by other new industries; allowed for mass production, etc.

No
More important - new inventions and innovations: concrete mixers, radios, telephones, washing machines, toasters; new materials such as Bakelite and rayon; mass marketing and effective advertising; availability of credit / hire purchase schemes; Republican policies of laissez faire, low taxation and tariffs; increased confidence led to increased investment in markets; expansion of US markets into Europe during the First World War; war loans, etc.