Located between the Stadium and the Dairy Building and across the canal from the Agriculture Building was the small building one guide called "a gem." The Mission Building was the most Spanish of all the Exposition buildings in its resemblance to a Spanish mission of old California. Buffalo architect George Cary designed it for the sponsors, fellow Buffalonians Carleton Sprague and George K. Birge. The east wing was apparently a duplicate of the Mission of Santa Barbara in California.
The building was a complex consisting of a chapel, cloisters, courts, and a shop which enclosed a courtyard garden. To extend the effect, the walls were "stained with age, and the tiled roof green with moss." (Pan-American Art Handbook, 1901). The garden featured cedars, coconut trees, palms and tropical plants. Within the courtyard was a fountain surrounded by marble colums. Parrots and macaws completed the effect.
The shop displayed Birge wallpapers, its interior walls covered in a wainscoting wallpaper imitating old Cordova leather, the upper walls covered in landscape papers of forests or mountains.
The chapel featured mosaics, a marble altar, bronze figures and stained glass windows on loan from Mrs. Leland Stanford, who had commissioned them in New York for installation in the Memorial Chapel on Stanford University's campus after the Exposition. The windows also served as the display of the J. & R. Lamb Company, stained glass fabricators. It was in the chapel that the Aeolian Organ Company installed one of its organs and provided daily recitals.
The Buffalo Pitts Company exhibited its equipment in the arcades that surrounded the courtyard.
The integration of the exhibits into the design of the building and the building's style both contributed to the sense of calm that visitors felt when they entered the courtyard. The crowded, noisy Exposition grounds and the frenetic commercial atmosphere of the other buildings were easy to forget when strolling the courtyard and listening to the fountain, or when relaxing on a chapel bench beneath the stained glass and mosaic, listening to organ recitals.