I never made that assertion. I do suggest that Smoot-Hawley
made the Great Depression worse.
There were many factors that produced the Great Depression:
the stock market crash, the crop failures in the midwest, and the collapse of the banking system because the FED did not do it job-a job it was assigned when formed-provide for an elastic currency.
The thing that made the great depression worse was the lack of debt discharge. Depression are purely a function of debt overload and the failure to quickly discharge debts causes them to linger.