Alexander Calder was born in Pennsylvania, son and grandson of American sculptors, and left his job as an engineer to become a sculptor himself. He was a prolific and playful artist, creating many mobiles. He also made stabiles (his non-kinetic sculptures), a large number of twisted wire miniature circus figures, and sets for theatre and ballets. He produced paintings, drawings, and jewellery. After being given a Masaya hammock in 1972, Calder commissioned some Nicaraguan weavers to make a host of new ones following eight of his own designs, along with a range of wall hangings. A collection of fourteen further hand-woven wool tapestries in limited editions then followed. The Whitney Museum of American Art has the largest body of work by Alexander Calder in any museum and the Philadelphia Museum of Art offers a view of works by three generations of Calders.