Alexander Calder (Philadelphia, 1898- 1976) was an American sculptor known as the originator of mobiles. While his early artwork was inspired by the circus, Calder began creating movable sculptures inspired by the abstract works of his friends Miro and Mondrian in the 1930s. After 1950, Calder became more focused on creating non-moving sculptures caned "stabiles." Calder studied at the Pennsylvania Academy of Fine Arts and the Art Students League in New York. While Calder is known primarily as a sculptor, he also applied his interest of abstract colored shapes to paintings is evidenced by his 1967 painting, "Crossroads." This painting was reproduced as a print in 1976 to celebrate the opening of the National Air and Space Museum.