<page_title> List of highest-income counties in the United States </page_title> <section_title> American Community Survey </section_title> <table> <cell> Mercer County <col_header> County </col_header> </cell> <cell> New Jersey <col_header> State </col_header> </cell> </table>
Mercer County in New Jersey stands among the highest-income counties in the United States.