The Black Heritage Trail of New Hampshire will unveil its first-ever historic marker in the city of Concord honoring legendary baseball player William Penn “Bill” Thompson. Thompson is believed to be one of the first African Americans to play on an integrated team in an organized league. He moved to Concord in 1890 and played catcher in the Concord Sunset League, which hosted many games at White Park. The marker will be placed near the State of New Hampshire Historic Marker, the classic moss green placard indicating the history of the park. The league, established in 1909, is the oldest after-supper amateur baseball league in the United States.