The document discusses four US presidents from 1981 to 2009. Ronald Reagan served from 1981 to 1989 and is known for decreasing government spending and lowering taxes to stimulate economic growth. George H. W. Bush held office from 1989 to 1993 and was both vice president under Reagan and father to later president George W. Bush. Bill Clinton served from 1993 to 2001 during a period of prolonged US economic expansion. George W. Bush was president from 2001 to 2009 and led the US response to the 9/11 terrorist attacks, initiating the War on Terror.