My understanding is that it was more the 9000 bank failures effectively created a credit crunch. Like if a bank closes and there's no replacement, then most small business were unable to get loans. Farmers who couldn't afford to plant new crops, factories can't improve equipment, inventory get's squeezed across the supply chain, ect. Exports were about 5% of GDP, suggesting that maybe tarrifs may have been the trigger but weren't the primary cause of the depression.