Alexander (Sandy) Calder

Pennslyvania-born Sandy Calder invented the mobile. Originally just called kinetic sculptures, Duchamp coined the term "mobile" to describe them. He was famous also for his Cirque Calder, a tiny circus made from "found" objects with which he traveled, putting on elaborate circus shows. During WWII, with the scarcity of metal, Calder fashioned his creations from wood, as his chess sets signify.