. "Mercer County"@en . "3785"^^ . . "1845Z"^^ . "3.20465"^^ . "3.36698e+06"^^ . . "2010Z"^^ . "0.3"^^ . "1.17585e+09"^^ . "1.17844e+09"^^ . . . . "Mercer County is a county located in the northwestern portion of the U.S. state of Missouri. As of the 2010 census, the population was 3,785, making it the second-least populous county in Missouri. Its county seat is Princeton. The county was organized February 14, 1845 and named for General John F. Mercer of the Revolutionary War."@en .