Kennedy knew that if the silver-backed United States Notes were widely circulated, they would have eliminated the demand for Federal Reserve Notes. This is a very simple matter of economics. The USN was backed by silver and the FRN was not backed by anything of intrinsic value. Executive Order 11110 should have prevented the national debt from reaching its current level (virtually all of the nearly $9 trillion in federal debt has been created since 1963) if LBJ or any subsequent President were to enforce it. It would have almost immediately given the U.S. Government the ability to repay its debt without going to the private Federal Reserve Banks and being charged interest to create new "money". Executive Order 11110 gave the U.S.A. the ability to, once again, create its own money backed by silver and realm value worth something.
President Kennedy was assassinated on November 22, 1963 and the United States Notes he had issued were immediately taken out of circulation. Federal Reserve Notes continued to serve as the legal currency of the nation. According to the United States Secret Service, 99% of all U.S. paper "currency" circulating in 1999 are Federal Reserve Notes. https://rense.com/general76/jfkvs.htm