According to the Artist's son, the present plaster of Ursa Major is probably the only extant example of this model which was conceived as part of an armillary sphere for a monument to Theodore Roosevelt in Washington D.C. Eric Gugler was the architect working on the project with Manship. When their design for the Roosevelt monument was rejected in favor of a figure of the late President, they reworked it for the 1964 World's Fair in Flushing Park, New York.

The 1964 sphere was very similar in concept to Manship's earlier Cycle of Life sphere is which reliefs representing the twelve signs of the zodiac were modelled on concentric bands intersecting to form the sphere. The 1964 version also included a few of the constellations around the North Star, one of which was Ursa Major.

Manship first modelled the reliefs in terracotta. From these terracottas two plaster casts were made--one to be sent to the foundry in Italy for casting in bronze and a second set for insurance against breakage. A complete set of the signs of the zodiac is in the collection of the Minneapolis Museum of Art, St. Paul, Minnesota. Manship also gave Eric Gugler casts in both media of some of the reliefs for his home on Sneden's Landing, New York.