The park only takes the name of the nearby cathedral, with the Archdiocese of Milwaukee holding no ownership of the site.
A mob of 5,000 people converged at the jail in 1854 to rescue Joshua Glover, a runaway slave captured and imprisoned by federal marshals.
During the American Civil War, parkland south of the courthouse was used as place to assemble for troops leaving for or returning from the front.
Since then, it has become a popular meeting place and host for events such as Jazz in the Park and the farmers' market, and as the site of the city's official Christmas tree.
This article incorporates text from the 1909 edition of Memoirs of Milwaukee County, by Jerome Anthony Watrous which is in the public domain in the United States.