The great depression was created by a perfect storm of events, credit was just one of the main culprits. Here is another event that prolonged it well beyond what it should have been:
“The Smoot-Hawley Tariff was more a consequence of the onset of the Great Depression than an initial cause. But while the tariff might not have caused the Depression, it certainly did not make it any better. It provoked a storm of foreign retaliatory measures and came to stand as a symbol of the ‘beggar-thy-neighbor’ policies (policies designed to improve one’s own lot at the expense of that of others) of the 1930s. Such policies contributed to a drastic decline in international trade. For example, U.S. imports from Europe declined from a 1929 high of $1,334 million to just $390 million in 1932, while U.S. exports to Europe fell from $2,341 million in 1929 to $784 million in 1932. Overall, world trade declined by some 66% between 1929 and 1934. More generally, Smoot-Hawley did nothing to foster trust and cooperation among nations in either the political or economic realm during a perilous era in international relations.”