This is Brancusi's first and smallest polished bronze Bird in Space. Its dimensions suggest that it derives from a plaster cast of the first marble Bird in Space (1923). However, the footing was changed, presumably benefiting from the innovations of the second marble Bird in Space (Philadelphia Museum of Art, 1950-134-19). The lower section of this new footing flares out like a skirt, a stylization unique among these works. The bottom of this element, like those of all versions of Bird in Space, is longer than it is wide; it traces an egg-shaped outline on the cylinder below.

Sidney Geist has identified this work as the subject of a famous photograph by Edward Steichen, taken at the Brummer Gallery in New York in 1926. The photograph was formerly assumed to portray Steichen's own bronze Bird in Space because it appears on the base that now supports that sculpture (Geist, Sidney. "The Birds." Review of Brancusi's Birds, by Athena T. Spear. Artforum {New York}, vol. 9, no. 3 {November 1970}, p. 80).

Apparently the Arensbergs purchased this bronze Bird in Space with only the black marble cylinder for a support. Photographs of their house reveal that the Arensbergs later displayed this work on the wooden base Brancusi sent them with Mademoiselle Pogany [III] (Philadelphia Museum of Art, 1950-134-21) in the early 1930s. When the two sculptures were acquired by the Philadelphia Museum of Art in 1950, the wooden based was shown beneath Bird in Space, but it was restored to Mademoiselle Pogany [III] in the 1970s. Ann Temkin, from Constantin Brancusi 1876-1957 (1995), p. 222.

The work of Brancusi redefined sculpture for a new century. Born in Romania but living in Paris after 1904, Brancusi aimed to develop a sculptural idiom that looked absolutely modern. His work moved beyond the verisimilitude and melodrama exemplified by the vastly popular sculpture of Auguste Rodin. Brancusi sought inspiration in ancient, folk, and exotic precedents that preceded or bypassed the classical Western tradition of sculpture. This brought Brancusi to simplified forms, reduction of details, and hand carving of materials.

The theme of the bird constitutes Brancusi's lifelong obsession, a subject he would explore in more than thirty marble and bronze versions over the course of four decades. The extreme reduction of detail that Brancusi evolved for his Bird in Space provoked the most notorious public misunderstanding of the artist's work. In 1926 a U.S. customs official insisted on labeling a version of the sculpture as a "miscellaneous household good" rather than a work of art, which would be tax-exempt for importation. After a long courtroom battle, the presiding judge stated that "while some difficulty might be encountered in associating it with a bird, it is nevertheless pleasing to look at and highly ornamental," and he ruled in Brancusi's favor. The dramatically long, slim sculptures represent Brancusi's idea of the essence of a bird, rather than a natural likeness; a slanting oval plane represents the head and beak, and a flared footing creates the powerful upward force that lifts the bird "in space." Twentieth Century Painting and Sculpture in the Philadelphia Museum of Art (2000), p. 44.