A post rock courthouse was built in Tribune in 1890, at a cost of $20,000. This three-story building was the hub of Greeley County, built on the public square. One of three oldest courthouses in Kansas, it is listed on the National Register of Historic Places. In 1975, the Courthouse became the Horace Greeley Museum.

Everything was held in the spacious building, such as, graduation, school plays, dances, movies, meetings, photography studio, the Doctor's dwelling, and of course, court was held in this building. Each office had a coal burning stove, drinking water bucket, and it was the duty of those employed in the offices to carry coal, start the fire in the stoves, get the pail of water, and other daily chores. During the depression a room was used for mattress making, and dispensing commodities to the qualifying families.

The judges bench, gavel, spittoon, witness chair, and the thirteen jurors chairs are displayed in the courtroom. It still contains the original jail cells in the basement.

The wainscoting, hinges, and curved stairway in the building are all original. The vault doors in the building are steel, and the doors have hand-painted scenes as adornment. There have been changes made through the years when the building was used as a courthouse, such as modernized water and bathrooms, but attention has been made to leave it as original as possible.

The entire three floors are dedicated to the collection and preservation of Greeley County history through displays, photos, period rooms, original newspapers from 1877, and city and genealogical records.