1) The Dow Jones Industrial Average (DJIA) is a stock market index that tracks the performance of 30 large, publicly owned companies in the United States.

2) The signing of the Magna Carta in 1215 laid the foundation for modern democratic principles and limited the powers of the monarchy in England.

3) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

4) The President of the United States serves as the head of state and the head of government, responsible for leading the executive branch and representing the nation domestically and internationally.