In 1885, the Morton County Commission decided to replace its small log courthouse, a building that had previously served as a saloon, keno hall, church, and schoolhouse.
County Commission president Elijah Boley championed a hillside location, proclaiming, “In ten years Mandan will be as large as Chicago and the hill north of the city will be the center of population.” On June 2, 1885, the county purchased Block 75 in the First Northern Pacific Addition from the City of Mandan for $2,300 (about $82,000 in 2025 dollars). Joseph Ardon, who farmed 12 miles northwest of Mandan, sold land in the area for the then-unheard-of price of $100 per acre. Workers leveled the hilltop and prepared a site of more than 12 acres.
County Commission president George Peoples secured an $8,000 (about $287,000 in 2025 dollars) bond for a new road that angled around the hill to the site.
The hill was terraced, and numerous steps were installed on its southern face. The courthouse overlooked the city as a monument to the pioneers' boom-era ambitions, when “Westward Ho!” remained a popular slogan. Records from the log courthouse between Main Street and First Avenue Northeast were moved into the new building in January 1886.
The two-story Richardsonian Romanesque brick building cost $35,000 (about $1,254,000 in 2025 dollars) and served as the Morton County Courthouse for more than 56 years. An addition was later built at the rear. The complex also included a sheriff's residence and jail west of the courthouse; jailer William Mackin was its first tenant.
By 1916, the disadvantages of the isolated location had become clear, and the county began a major landscaping project. The hill's southern face was reshaped into five terraces. A broad concrete stairway connected Collins Avenue with the courthouse walk, and a driveway was built from the foot of the hill.
Fire destroyed the courthouse May 15, 1941. Residents noticed smoke pouring from the upper windows and roof around 5 p.m. County commissioners were meeting inside and initially did not know the building was burning.
Despite the fire department's rapid response, the courthouse could not be saved. Firefighters concentrated on protecting the adjacent jail and sheriff's residence. The building was insured for $60,000 (about $1,313,000 in 2025 dollars).
Construction of a replacement had to wait until after World War II. Salvageable records were transferred to the Mandan Memorial Building, now Mandan City Hall, where county business was conducted for 14 years. The present $590,000 (about $6,987,000 in 2025 dollars) Memorial Courthouse was completed in early 1956.