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
Prior to independence, several colonies had already experimented with term limits. The Fundamental Orders of Connecticut of 1639, for example, prohibited the colonial governor from serving consecutive terms, setting terms at one year's length, and holding "that no person be chosen Governor above once in two years." Shortly after independence, the Pennsylvania Constitution of 1776 set maximum service in the Pennsylvania General Assembly at "four years in seven". Benjamin Franklin's influence is seen not only in that he chaired the constitutional convention which drafted the Pennsylvania constitution, but also because it included, virtually unchanged, Franklin's earlier proposals on executive rotation. Pennsylvania's plural executive was composed of twelve citizens elected for the term of three years, followed by a mandatory vacation of four years.