The massive U.S. loans to the Allies, and the subsequent American entry into the war, could not have been financed by the relatively hard-money, gold standard system that existed before 1914. Fortuitously, an institution was established at the end of 1913 that made the loans and war finance possible: the Federal Reserve System. By centralizing reserves, by providing a government-privileged lender of last resort to the banks, the Fed enabled the banking system to inflate money and credit, finance loans to the Allies, and float massive deficits once the U.S. entered the war. In addition, the seemingly odd Fed policy of creating an acceptance market out of thin air by standing ready to purchase acceptance at a subsidized rate, enabled the Fed to rediscount acceptance on munitions exports.
The Federal Reserve was the outgrowth of five years of planning, amending, and compromising among various politicians and concerned financial groups, led by the major financial interests, including the Morgans, the Rockefellers, and the Kuhn, Loebs, along withtheir assorted economists and technicians.
Read it all at: https://www.lewrockwell.com/2015/12/murray-n-rothbard/wall-street-banks-american-foreign-policy/