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.
Donald Trump 2020 presidential campaign
Since his three immediate predecessors (Bill Clinton, George W. Bush and Barack Obama) won reelection, if Trump is reelected, it would be the first time in American history that there have been four consecutive presidents who were elected to two terms. If Trump completed his second term on January 20, 2025, he would be 78 years old and would have become the oldest person to serve as president, surpassing Ronald Reagan (who was 77 when he left office in 1989).