Mercer County courthouse is located at 209 South Broad Street, Trenton NJ 08650; phone: 609‑571‑4000.
Officially founded in 1838 and carved out of other surrounding counties, Mercer County has a historical impact that reaches back to the pivotal battles of the American Revolutionary War.
General George Washington led his famous December crossing of the Delaware and routed the Hessians right here in Mercer County. That turning point of our country's struggle for independence and liberty is just one of the many historically significant things to have happened here in Mercer.
Further, when the Revolutionary War concluded, the City of Trenton and Princeton Township took turns serving as the temporary Federal Capital.
Mercer County is named in honor of General Hugh Mercer, a distinguished hero of the Revolution, who died from wounds inflicted during the Battle of Princeton in 1777.
Other notable historical figures of America's past have also become part of the history of Mercer County. Former Vice President Aaron Burr, Presidents Grover Cleveland and Woodrow Wilson, and the Marquis de Lafayette have all become part of the history of Mercer County.
Mercer County also has the dubious distinction of being the famed landing spot for a Martian invasion of the United States. In 1938, in what has become one of the most famous radio addresses of all time, Orsen Welles acted out his 'War of the Worlds' invasion. Wells landed his imaginary aliens on Mercer County soil, using what is now West Windsor Township as the point of first contact. And our history is continually being added to daily by our residents.