Which famous abstract sculpture by Alexander Calder is located in Chicago's Federal Plaza?

Alexander Calder's famous abstract sculpture located in Chicago's Federal Plaza is known as Flamingo. This striking piece, completed in 1974, features a vibrant red color and embodies the artistic principles of balance and movement that Calder is acclaimed for. The sculpture stands 53 feet tall and consists of a combination of curves and angular shapes, symbolizing both the natural forms of a flamingo and the innovative spirit of modernist art.

Flamingo not only acts as a visual focal point within Federal Plaza but also engages its surroundings, providing a dynamic interplay with the urban landscape and inviting viewers to appreciate the sculpture from various perspectives. Calder’s sculpture is emblematic of his larger body of work, where he often explored the themes of abstraction and kinetic energy.

The other choices, such as Cloud Gate, Untitled, and Large Reclining Figure, represent different works by other artists or different locations, hence they do not pertain to the sculpture in question.