During his lifetime, Alexander Calder was recognized as one of the most original American artists of the interwar and postwar years. As a sculptor, painter, illustrator, printmaker and designer, he combined elements of European modernism with a unique approach to form that was influenced by his early experiences as a mechanical engineer.

Calder’s major contribution to the history of modern sculpture was the mobile, a term coined by Marcel Duchamp. In this new art form, Calder made movement a crucial element, at first by working with motors and then by suspending his sculptures from the ceiling so that they would be set into motion by the movement of air. The mobiles synthesized Constructivist methods with biomorphic imagery related to Surrealism. Two White Dots in the Air is a classic example of this genre, in which abstract shapes that evoke forms from nature such as fins, wings, leaves, or cosmic bodies, are gracefully suspended from curving wires. As these forms shift and rotate in often unpredictable ways, the sculpture seems possessed of its own life.