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.
1876 United States presidential election
It was widely assumed during the year 1875 that incumbent President Ulysses S. Grant would run for a third term as president in spite of the poor economic conditions, the numerous political scandals that had developed since he assumed office in 1869, and a long-standing tradition set by the first president, George Washington, not to stay in office longer than two terms. Grant's inner circle advised him to go for a third term and he almost did, but the House, by a sweeping 233 to 18 vote, passed a resolution declaring that the two-term tradition was to prevent a dictatorship. Late in the year, the president withdrew from the running for 1876.