Just read The Truth about Trade in History.
“Economists and historians continue to debate how important the Smoot-Hawley tariff was in causing the Great Depression.11 Whatever the degree, the effect certainly was adverse and the tariff was certainly bad policy. As Figure 2 indicates, world trade virtually collapsed following passage of the Smoot-Hawley tariff. Thus, if that tariff was not the single cause of the Great Depression, it certainly made a bad situation worse.”
oops.
Here an article I've posted often before. Fairly long, but it presents the money supply and Fed case very well.
The great depression and its offspring, the New Deal, could both have been avoided if the Federal Reserve had performed the task assigned to it. All the Federal Reserve had to do to avoid the Depression and the subversion of the American constitutional order was to purchase $1 billion in government securities during the 10-month period from December 1929 to October 1930. The result would have been an increase, instead of decrease, in high-powered money, and the banking crisis that began in the autumn of 1930 would not have occurred.
The Fed's "Depression" and the Birth of the New Deal
Rather than increasing the money supply, Fed decisions decreased it severely.
In 1930 trade was a tiny part of the US economy. Smoot-Hawley meme is a blatant rewriting of history. It is almost comical and certainly Goebbelesque.