MARSHALLTOWN, the county seat of Marshall County, Iowa, United States, is situated on the Iowa river at the junction of several railways, and in the midst of a grain and stock producing region. Among its numerous industries are sugar-refining, waggon-making, and the manufacture of.barbed steel wire for fencing purposes. The population was 3218 in 1870 and 6240 in 1880, and has since increased rapidly.