The Federal Reserve Act of 1913 was an act of Congress that was signed into law by President Woodrow Wilson. This move was partly motivated by the Panic of 1907. The law created the Federal Reserve System which is the central banking system of the United States. It also required all federally chartered banks to join the federal reserve system.
Opportunity cost is the cost of the options that one is not choosing. This means that if one has to choose between A and B, opportunity cost is the cost of "giving up B" when one chooses A.