The Pennsylvania legislature established this park in 1867 on former Allegheny Arsenal grounds, making the ground under your feet one of Pittsburgh's oldest public parks. The park covers several blocks in the North Side and was designed in the pastoral tradition of Frederick Law Olmsted, with curving paths and open meadows intended for public recreation. The Allegheny Arsenal, located immediately east of here, was established in 1814 and produced arms and ammunition through the Mexican-American War and the Civil War.
In September 1862, an explosion in the Arsenal's cartridge-filling room killed 78 workers, mostly young women and girls who had taken the dangerous jobs because they needed the income. It was one of the deadliest industrial accidents of the Civil War era. The park replaced the Arsenal after the war, converting military land to public use.
The North Side was an independent city called Allegheny until Pittsburgh annexed it in 1907 over fierce local opposition. The residents of Allegheny had considered their city superior to Pittsburgh in refinement and culture, and they never entirely made peace with annexation.