Traill County, North Dakota: History
The Dakota Territory legislature created the county on January 12, 1875, with areas partitioned from Burbank (now Barnes), Cass, and Grand Forks Counties. It was named for Walter John Strickland Traill, an employee of the Hudson's Bay Company and son of Canadian pioneer Catharine Parr Traill. The first county building was a small single-story building in Caledonia. Several replacement courthouses were built during the late 19th century and several votes to move the county seat to Mayville narrowly failed. Efforts to move the county seat to Hillsboro were more successful, and all county records were moved there in 1890. Construction of the current county building began in 1905; it is now listed on the National Register of Historic Places.
The county boundaries were altered in 1881 and in 1883. It has maintained its current configuration since 1883.