The Ansel B. Cook House was built by its namesake on the site of the first permanent dwelling in Libertyville. In his will, Cook deeded his home to be used as a library. After a facade reconstruction, Cook Memorial Library opened in 1921. In 1968, following construction of the present Cook Memorial Library, the Cook mansion became the headquarters of the Libertyville-Mundelein Historical Society. Some of the rooms are reserved for museum-type displays while others depict Victorian period rooms. The home is open Sundays during June, July and August from 2 to 4 p.m. They also host a Victorian Christmas Open House on designated weekends in December.