Arizona became a Territory of the United States in 1863 and over the next several months counties were organized.  Tucson, the seat of Pima County, became the capital of the Arizona Territory in 1867 and remained so for ten years.  From 1866 to 1868, Pima County business was conducted in some buildings rented from Solomon Warner.  Increased population and activity made it clear that Pima County needed a permanent courthouse.

After moving the Court to several more rented locations, the county purchased a lot at the corner of Court and Ott Streets from Mark Aldrich for $200.  Bid notices were posted in the Southern Arizonan in October of 1867.  Charles Meyer was awarded the contract on January 1, 1868.  The bid amount was $15,500 and later $150 was added for two additional doors.  Specifications called for a rock foundation, "walls of adobe made of good dirt well mixed with straw," and a step in front of each doorway, "made of good sound mesquite timber."  This building was typical of those built in southern Arizona in those days with its flat, unadorned exterior and deeply recessed doors and windows.  Meyer finished the building in May of 1868 but it was not yet painted.  Bids were let out to give the building three coats of paint on the interior.

The Southern Pacific Railroad reached Tucson in March 1880, and continued construction eastward through Benson, Wilcox, and Bowie.  This brought more new settlers and more commerce to the still vast and undivided Pima County.

A larger Courthouse was needed.  Additional land at the northwest corner of Pennington and Court Streets was purchased from stable owner and Sheriff Robert N. Leatherwood.  On this site a second, larger courthouse was built in 1881.  County Commissioners W. W. Williams, James Toole, and William S. Oury contracted with John Harlow to build the new courthouse, a two-storied brick building with a grey stone foundation.  The cruciform building had two side wings topped by gable attics and a tower with a cupola surmounting the center.  Called "the pride and joy of the Territory," this courthouse was used through the rest of the Territorial era and until after Arizona became a state on Valentine's Day, 1912.  It was torn down in 1927 and replaced beginning in 1928.

This third Pima County courthouse was built on the site of the previous courthouse.  Commissioned by County Supervisors Joseph M. Ronstadt, John McK. Redmond, and Robert E. Butler, it was designed by Tucson architect Roy W. Place and built by Herbert Brown, contractor.  It cost around $350,000.  When built, there was some controversy about the color selected and the style of the building.  An outstanding example of Spanish Colonial Revival architecture, the brick structure, covered with pink stucco, is traced by Moorish arches opening onto a central patio in the rear of the building and a massive cement dome covered by ceramic tile.

When excavation for the new courthouse began, it was discovered that the building would cover where the southwest corner and part of the east wall had surrounded the old Tucson Presidio.  A section of the wall, uncovered in the excavation, has been saved and is on display in the courthouse Assessor's Office as a memorial to the early settlers of Tucson.  A stone marker in the courtyard indicates the location of the presidio's wall.  The building fronted on Court Street until, in the early 1970's, that portion of the street was removed and covered over to create Presidio Park.

Called the "old" Pima County Courthouse since the Superior Court Building was erected in 1972, it is still in daily use by the County as a public building.  On its fiftieth birthday in 1978, The Pima County Courthouse was named a National Landmark in the National Register of Historic Places.