George Washington
At the end of his second term, Washington retired for personal and political reasons, fatigued and disgusted with personal attacks, and to assure a truly contested presidential election could be held. He did not feel bound to a two-term limit, but his retirement ultimately set precedent. The two-term limit to the presidency was formalized with the 1951 adoption of the Twenty-second Amendment to the United States Constitution. Washington is often credited with setting the principal of a two-term presidency, but it was Thomas Jefferson who first refused to run for a third term on political grounds.
Term limits in the United States
A total of 8 presidents served two full terms and declined a third and three presidents served one full term and refused a second. After World War II, however, an officeholder class had developed to the point that congressional tenure rivaled that of the U.S. Supreme Court, where tenure is for life.