Only president not born in the continental U.S.

OBAMA

This 44th U.S. president was born in Honolulu and served two terms starting in 2009.

This clue refers to Barack Obama, who was born in Hawaii—the only U.S. president not born in the continental United States (the 48 connected states). While Hawaii is a U.S. state, its location in the Pacific Ocean makes it geographically separate from the mainland. The answer plays on the fact that all other presidents were born in the contiguous U.S. or its territories before statehood. The straightforward nature of the clue means no wordplay is involved.