Walker began preserving cartoon artwork in the 1940s, when he discovered King Features Syndicate using Krazy Kat drawings to sop up water leaks.

[3][4] Two years later, the landlord decided he could rent the mansion for more, forcing a move to a space on Field Point Road in Greenwich, Connecticut.

An attempt was made to relocate to three floors of the Empire State Building in New York City in 2007, but the deal fell through for reasons that are disputed.

It consists almost entirely of donations from artists, including Chester Gould (Dick Tracy), Hal Foster (Prince Valiant), Bil Keane (Family Circus), political cartoonist Jeff MacNelly, Mike Peters (Mother Goose and Grimm), Milton Caniff (Terry and the Pirates), Dik Browne (Hägar the Horrible), Stan Lee (Spider-Man), Rube Goldberg and others.

Among its prized possessions is the first drawing of Mickey Mouse, by Ub Iwerks for the character's film debut in Plane Crazy (1928).