The 22nd Amendment to the United States Constitution limits the number of terms a person can serve as President to two. Ratified in 1951, it was a response to Franklin D. Roosevelt, who was elected to four terms. The amendment ensures that no individual can hold the presidency for more than ten years, which includes time served as a vice president if they assume the presidency mid-term. This amendment was designed to promote democratic principles by preventing any one person from gaining too much power over an extended period. It reflects the belief that regular leadership changes are essential for a healthy democracy.