Sherman County is a county located in the U.S. state of Nebraska. As of the 2010 census, the population was 3,152. Its county seat is Loup City. The county was created in 1871 and later organized in 1873. It was named after American Civil War General William Tecumseh Sherman.In the Nebraska license plate system, Sherman County is represented by the prefix 56 (it had the fifty-sixth-largest number of vehicles registered in the county when the license plate system was established in 1922).