American artist Alexander Calder redefined sculpture by introducing the element of movement, first though performances of his mechanical Calder's Circus and later with motorized works, and, finally, with hanging works called "mobiles." He was the first to use wire to create three-dimensional line "drawings" of people, animals, and objects. These "linear sculptures" introduced line into sculpture as an element unto itself.
He came from a family of professional artists. His grandfather, sculptor Alexander Milne Calder, was born in Scotland, immigrated to Philadelphia in 1868, and is best known for the statue of William Penn on top of Philadelphia City Hall's tower. His father, Alexander Stirling Calder, was also a well-known sculptor and his mother, Nanette Lederer Calder, was a professional portrait artist, who studied at the Sorbonne in Paris and the Pennsylvania Academy of the Fine Arts. Calder's parents did not want him to suffer the life of an artist, so he decided to study mechanical engineering. He ended up in art despite his parents objections. In 1926, after showing paintings at The Artists' Gallery in New York he moved to Paris where he met Joan Miró, who became an important influence and close friend. He enrolled in the Académie de la Grande Chaumière, and had a studio in the Montparnasse Quarter. While in Paris, Calder met and became friends with a number of avant-garde artists, including Fernand Léger, Jean Arp, and Marcel Duchamp. A visit to Piet Mondrian's studio inspired him to embracing abstract art.
The forms and colors of Miro and Mondrian figured prominently in his sculpture and prints throughout his career. Dating from 1931, Calder’s sculptures of movable parts powered by motors were christened “mobiles” by Marcel Duchamp, a French pun meaning both "motion" and "motive." In 1952 he represented the United States at the Venice Biennale and was awarded the main prize for sculpture.
In addition to sculptures, he painted and created prints, using primary colors with groups of geometric shapes, often in motion. He often used his posters and prints for advocacy and to protest the Vietnam War. Two months after his death, the artist was posthumously awarded the Presidential Medal of Freedom, the United States' highest civilian honor, by President Gerald Ford. However, representatives of the Calder family boycotted the January 10, 1977 ceremony "to make a statement favoring amnesty for Vietnam War draft resisters".