Maine was admitted to the Union on March 15, 1820. The state's U.S. senators belong to class 1 and class 2. Republican Susan Collins (first elected in 1996) and Independent Angus King (first elected in 2012) are Maine's current U.S. senators, making Maine one of seven states to have a split United States Senate delegation. William P. Frye was Maine's longest serving senator (1881–1911). Maine is one of fifteen states alongside Arizona, Colorado, Florida, Georgia, Hawaii, Idaho, Indiana, Louisiana, Massachusetts, Minnesota, Missouri, Nevada, South Dakota and Utah to have a younger senior senator and an older junior senator.

List of senators

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