Ron Paul was born in Pittsburgh, Pennsylvania on August 20, 1935. He received a B.S. degree in biology from Gettysburg College in 1957 and a M.D. degree from the Duke University School of Medicine in 1961. He served as a flight surgeon in the United States Air Force from 1963 to 1965 and then the United States Air National Guard from 1965 to 1968. Afterward, he opened a private practice in obstetrics and gynecology in Texas. He served in the United States Congress from 1976 to 1984, and again from 1996 to the present. He has devoted his political career to the defense of individual liberty, sound money, and a non-interventionist foreign policy. He is the founder of the advocacy group Campaign for Liberty and has been called the "intellectual grandfather" of the Tea Party movement. He has written several books including The Case for Gold, The Revolution: A Manifesto, End the Fed, and Liberty Defined: 50 Essential Issues That Affect Our Freedom.