Born in a family of sculptors, he travels from his birth place, Philadelphia, to New-York and Paris, where he participated to artistic events. He was inspired by Arp and Miro and his works are abstrait and made out of wood and wire. He joined the Abstraction-Creation movement and in 1931, he presented his first 'mobile' activated manually or with a motor at the gallery Vignon, as he expressed his wish to create 'Moving Mondrians' that will be called 'Stabiles' by Arp, when they where not meant for movement in space. He creates his mobiles and stabiles every time bigger in size. Nowadays, he is known as one of the big names of modern sculpture.