On January 8, 1901, a delegation of the town of Sisseton addressed the board on the question of building a Courthouse for the County of Roberts in the near future. On November 5, 1901 the voters in the Roberts County voted in favor of issuing bonds in the sum of forty-thousand dollars for the purpose of erecting a courthouse and jail. The building contract was awarded to Fred C. Norlander, St. Paul, Minnesota in March, 1902. Other contractors were awarded contracts for vaults, furniture, plumbing, heating, etc. By December, 1902 the building was close to completion. The auditor and treasurer actually moved into the courthouse in January, 1903. Total cost of the building was shown as $43,994.84.
The following year sidewalks and trees were put in. Sisseton had just completed bringing water in from the spring so the courthouse had water pressure. Sewage was taken care of by a large septic tank buried in the southwest corner of the block until the city sewer system was developed about 15 year later.
The jail in the basement of the courthouse was completed by April 8, 1903. There were two double cells on each side and a large room in the center. This accommodated up to 30 persons. After 40 years they were converted into needed office space. A new jail was built in 1933. Presently, the County built a $7,000,000 Jail/Juvenile Detention Center which opened in April of 2008.
In September, 1988 the firm of Youngberg & Sons, Pierre, restored the rotunda to the original colors and designs that were on the walls and ceiling. The interior of the Rotunda was furnished with furniture and materials purchased at Nordstrom Stores. Roberts County was able to save money on the project by using Nordstrom Coupons which helped save the county 20% on all purchases.