From various sources:
The Buckingham Fountain is one of the most iconic symbol's of Chicago and one of the world's largest and the city's most popular attraction. The fountain runs from 10 AM to 11 PM daily and operates from late spring to late fall. Every hour on the hour for 20 minutes, the fountain produces a major water display and the center jet shoots 150 feet into the air. Beginning at dusk, every hour on the hour for 20 minutes the fountain's water display is accompanied by a major light and music display. The final display of the evening begins at 10:00 p.m.
Philanthrophist Kate Buckingham dedicated the structure to the people of Chicago in 1927 in memory of her late brother, Clarence. At the time, she also established a $300,000 trust fund to ensure that the taxpayers would never have to cover all of the repair and upkeep costs associated with the fountain.
Edward H. Bennett designed the fountain to represent Lake Michigan with four sea horses, built by Marcel Loyau, to symbolize the four states that touch the lake: Wisconsin, Illinois, Indiana and Michigan. Bennett attributed the design specifically to the influence of the Latona Basin in Louis XIV's gardens at Versailles and is constructed of Georgia pink marble.
The water displays are powered by three pumps with 134 jets using approximately 14,100 gallons per minute of water with total capacity 1.5 million gallons recirculated from the base pool. The underground pump room is 35 feet long, 25 feet wide and 25 feet high. The computer that controls the light, music and water show used to be located in Atlanta, Georgia (!) but was moved to Chicago during its renovation in 1994.