Alexander Calder (b. 1898, Pennsylvania, d. 1976, New York) is one of the most acclaimed and influential sculptors of the twentieth century. He is renowned for the invention of the mobile, a kinetic construction of suspended abstract elements that describe individual movements, moving and balancing in changing harmony. Calder also devoted himself to making outdoor sculpture on a grand scale from bolted sheets of steel, many of which stand in public plazas in cities throughout the world. Pace Gallery has represented the Calder Foundation since 1984.