Columbia is a town in, and the parish seat of, Caldwell Parish, Louisiana, United States. The population was 277 in 2020. The land that became Columbia was first cleared by Daniel Humphries in 1827. A store was built a few years later the only settlement between Monroe, Louisiana, and the settlements of the Black River was formed. The harbor became a bus…Columbia is a town in, and the parish seat of, Caldwell Parish, Louisiana, United States. The population was 277 in 2020. The land that became Columbia was first cleared by Daniel Humphries in 1827. A store was built a few years later the only settlement between Monroe, Louisiana, and the settlements of the Black River was formed. The harbor became a busy port for shipping cotton by steamboats and Packet boats until the arrival of the railroad. In February 1864 Columbia was the location of a skirmish between Federal and Confederate troops during the Civil War and there are several plantations in the area.