Alexander Calder was an American sculptor best known for inventing the mobile—kinetic sculptures that move gracefully with air currents. Trained as an engineer, he brought a strong sense of balance and mechanics into his art. Alongside his mobiles, he also created large-scale stationary sculptures called “stabiles,” many of which are installed in public spaces around the world. Calder played a major role in modern art by introducing movement as a central element of sculpture.