Located in the heart of southern Minnesota on the western edge of an area once known as the "Big Woods," Blue Earth County contains many rivers which served as natural highways for the Indians. The Blue Earth River enters the county from the south and joins the Minnesota River at its great south bend, which forms the northern border of the county. The name "Blue Earth" is a translation of the Dakota Indian word "Mahkato," meaning "greenish blue earth." The Indians in the vicinity used the blue-green clay to color their faces for ceremonial events.
The official organization of the county was effected by an act of legislature and passed in 1853. The settlement of the county dates from 1852, when P.K. Johnson and Henry Jackson, both prominent residents of St. Paul, Minnesota, arrived by steamboat at the mouth of the Blue Earth River. Here they proceeded to make plans for the townsite which was to become Mankato. The honor of naming the townsite was given to Mrs. P.K. Johnson and Mrs. Henry Jackson, who selected the name Mahkato. In legal documents a mistake was made in transcription and the name became Mankato.
Agricultural possibilities attracted many settlers to Blue Earth County in the 1850s and 1860s. The big land rush years of 1854 – 1857 saw more people settling on farms than in towns. They came by steamboat, covered wagons, stagecoach, and later by train. If gold was the magnet in California, rich black dirt was the attraction in Minnesota. The area today is one of the best agricultural areas and Mankato one of the largest industrial cities in the state.