How did the Great Depression affect the lives of American citizens?
It varied greatly according to where you lived.
I asked my father that very question and his response was his family did not notice much change at all. My grandfather was a well-educated man who worked in Boston. His job and the need for it was unaffected by the depression.
But mill workers around the country were affected as orders for things like automobiles, steel, aircraft, home appliances declined. And so there were many layoffs among such industries but few shut down entirely. That was the make-up of the entire northeast and mid-west.
But as soon as you entered the farmland of the plains, thing got desperate quickly. West of the Mississippi in those days there was very little manufacturing, farming was king. And the stock market crash in and of itself would not have effected the farmers had they not been stricken by a natural disaster.
For generations, farmers had planted and repeated one type of produce on their land. The soil became poor. Then a drought hit in 1930, followed by another in 1931 and 1932. Crops failed, land stood fallow, and the winds which blew across the plains picked up that poor soil and blew it into unimaginable dust storms. A few dust storms were so great their effect was felt in Boston and New York.
When the farmers could not pay the banks on the mortgages the banks held there came foreclosures. And when those same farmers could not afford to pay the debts they all owed to various merchants, they too began to fail.
These plains farmers moved to California on the promise that the central valley there could more than support all of them. But that just was not true. This caused a huge strain on California's resources.
All Americans were affected by the depression to one extent or another. But it depended greatly upon your source of income and to what degree that source itself was affected by the depression.