Justice William J. Brennan Jr. Courthouse or The Hudson County Courthouse or is located in Jersey City, Hudson County, New Jersey, United States. The six-story structure was originally built between 1906 and 1910 at a cost of $3,328,016.56. It is considered to be an outstanding example of the Beaux-Arts architectural style in the United States. In 1984, the Hudson County Board of Chosen Freeholders renamed the building in honor of Supreme Court Justice William J. Brennan Jr.