The Bloody Benders, America's First Serial Killers
In 1870, Ma, Pa, Mary, and Laura Ingalls left their home in southeast Kansas, where they had lived for about a year, and headed back to Wisconsin. Their Kansas home was later the basis for her book The Little House on the Prairie.
That same year, a group of new families moved into the area. They were Spiritualists, a religion that was totally foreign to the homesteaders already in the new state. Two of the families moved away within a year. The others kept to themselves, with the exception of the Benders. What they brought to Kansas turned out to be a nightmare of murder on a mass scale. Read the story of the Bloody Benders in an article I wrote for mental_floss.