Alexander Calder was one of the most original artists of the twentieth century and a major figure in American art. Renowned for his mobiles and stabiles, he also created the beloved Calder Circus, an early performance piece now preserved at the Whitney Museum. He was a contemporary and friend of Marcel Duchamp and Joan Mir and collaborated with Martha Graham. His wife, Louisa, was a grandniece of Henry and William James, a liberal society girl from...