b) James Monroe

James Monroe, the fifth President of the United States, was the only president other than George Washington to run virtually unopposed in the presidential election of 1820. Monroe’s presidency, known for the “Era of Good Feelings,” was marked by a sense of national unity and political harmony. His unopposed re-election underscored the lack of significant political opposition during this period and represented a high point of one-party rule in the early years of the American republic.