The Plaza was created in 1864 when the Prescott Original Townsite was surveyed and mapped by Robert Groom, who followed the typical 19th Century concepts of town planning. Laying out the townsite in a grid, Groom set aside two city blocks for government purposes – the Plaza and the Capitol Block. They were connected by Liberty Street, now Union Street. As the Territorial Capital and the seat of Yavapai County government, Prescott was an important town (although few would agree that it qualified as a town) in a vast wilderness. Yavapai County alone initially included 65,000 square miles of land, most of it inaccessible and inhabited by hostile peoples who were not welcoming to the new settlers.

Originally, the Plaza was a vacant piece of land with Ponderosa pine trees. Soon, however, the trees had been cut down for building materials and sheep were grazing on the tall grass. Wells were drilled on the four corners of the Plaza and fencing soon followed, although the tall grass was still present when the new pink brick courthouse was completed in 1878. As the center of the small community of Prescott, it became a popular gathering place, as it is today.

The first Prescott Courthouse was located in the 100 block of North Cortez Street. The first structure, other than small storage buildings and shacks, to be constructed on the Plaza was the 1878 Courthouse. It was followed by the construction of a chapel, bandstand, water tank and a decorative fountain. Trees, grass and a cactus garden were planted, gravel paths were laid out and a fence was erected. This layout for the bandstand, fountain and the walkways still exists today. Today, the Plaza is surrounded by a park-like setting of grass and trees, which in turn is ringed by commercial businesses and government offices on the four streets facing the Plaza.

By 1916, the courthouse was inadequate and plans were underway for a new building in a neo-classical style. The old courthouse was torn down in 1916. The site was not cleared completely, however, as the bandstand, fountain and graveled pathways remained.

The cornerstone was laid for a new courthouse on October 19, 1916. Behind the cornerstone a copper box was installed which was to be opened in 100 years. The box contains photographs, receipts from local businesses and three issues of Yavapai Magazine.

Many celebrations of every kind have been held on the Plaza – Independence Day gatherings began in 1864 and many have been held on the Plaza.