Answer:
The President of the United States when the Stock Market collapsed was President Herbert Clark Hoover.
Step-by-step explanation:
President Herbert Clark Hoover was the 31st president of the United States of America from 1929 to 1933 during the Stock Market Collapse. He was a businessman and engineer before he ventured into politics.
His economic principle was the laissez-faire approach. This was a laid back and non participatory approach to governance. He felt that economic assistance would make people stop working. He believed business prosperity would trickle down to the average person.
He did not believe it was the responsibility of the government to bail people of businesses out of trouble. His lack of response caused the Depression to get worse.