Alexander Calder was an American artist best known for his invention of the mobile and his wire sculptures. “My whole theory about art is the disparity that exists between form, masses, and movement,” the artist once said. Born to artist parents on August 22, 1898 in Lawnton, PA, Calder turned to art in the 1920s and moved to Paris to continue his studies in 1926, where he was introduced to the European avant-garde through performances of his Cirque Calder (1926–1931). “I was very fond of the spatial relations,” he said of his interest in the circus. “The whole thing of the—the vast space—I’ve always loved it.” Notably, it was his friend Duchamp that coined the term “mobile,” a pun in French meaning both “motion” and “motive,” during a visit to Calder’s Paris studio in 1931. The earliest mobiles moved by motors, but Calder soon abandoned these mechanics and designed pieces that moved by air currents or human interaction. The artist lived in both Roxbury, CT, and Saché, France, before his death on November 11, 1976 in New York, NY. Today, his works are held in the collections of such major museums as The Museum of Modern Art in New York, the National Gallery of Art in Washington, D.C., the Whitney Museum of American Art, New York, the Art Institute of Chicago, and the Tate Gallery in London.