Marion is a city in LaMoure County, North Dakota, United States. The population was 125 at the 2020 census. The city was founded in 190…Marion is a city in LaMoure County, North Dakota, United States. The population was 125 at the 2020 census. The city was founded in 1900 as Elmo, but changed its name to Marion in 1902. The new name came from Marion Mellen, daughter of Northern Pacific Railway president Charles Sanger Mellen. Marion was located at the end of a Northern Pacific branch line starting in Casselton and known as the "lady line" due to the many cities bearing female names located alongside the tracks. The line was in place in Marion until 2002, when eventual owner Red River Valley & Western filed for abandonment.