The Sesqui-Centennial International Exposition of 1926 was a world's fair in Philadelphia, Pennsylvania to celebrate the 150th anniversary of the signing of the United States Declaration of Independence, and the 50th anniversary of the 1876 Centennial Exposition.
The honor of hosting this celebration was awarded to Philadelphia in 1921. Initial grand plans were scaled down tremendously by the time the fair opened. The original director of the exposition, Colonel David C. Collier, resigned in protest over these budget cuts. His replacement, Captain Asher C. Baker, retired due to illness days before the festival opened, leaving things in the hands of E. L. Austin. Baker died less than two weeks later.
The senior draftsman for the design of the exposition buildings was a young Louis Kahn, later a world-renowned architect, then working under City Architect John Molitor. Sculptor Charles Tefft as chosen as the director of sculpture for the fair. 
The fair opened on May 31, 1926, and ran through November on grounds bounded by 10th Street, Packer Avenue, 23rd Street, and the U.S. Navy Yard (Terminal Avenue) in South Philadelphia. Originally known as League Island Park, these grounds are now occupied by FDR Park, Marconi Plaza, Packer Park Residential Neighborhood, the four facilities of Philadelphia's massive South Philadelphia Sports Complex (Wachovia Spectrum. Wachovia Center, Lincoln Financial Field, and Citizens Bank Park), and the Philadelphia Eagles training complex which now occupy that portion of the grounds which from 1933 to 1993 were the site of Philadelphia Naval Hospital (demolished 2001).
The fair drew a much smaller crowd than anticipated (about 10 million people). It ended up unable to cover its debts and was placed into receivership in 1927, at which point its assets were sold at auction.
Organizers constructed an 80 foot replica of the Exposition's symbol, the Liberty Bell, covered in 26,000 light bulbs, at the gateway to the festival. Sesqui-Centennial Stadium (later known as Philadelphia Municipal Stadium, and after 1964, John F. Kennedy Stadium) was built in conjunction with the fair. Also on display at the exposition was the Curtis Organ, still one of the largest pipe organs in the world. In 1926 the first bridge (later renamed Benjamin Franklin Bridge) spanning the Delaware River between center city Philadelphia and Camden, New Jersey, was built in anticipation of the attending crowds.
Key speakers at the opening ceremonies were Secretary of State Frank B. Kellogg, Secretary of Commerce and future President Herbert Hoover, and Philadelphia Mayor W. Freeland Kendrick. At the center of the exposition along the main thoroughfare on a segment of south Broad Street known as the Southern Boulevard Parkway was the Forum of Founders consisting of the Court of Honor, the Liberal Arts and Agriculture Buildings, a group of sculptures and the Stairway of Nations facing on the opposing side the spectacular Tower of Light.
The Exposition also included an amusement area, located within League Island Park. The area was designated as “Treasure Island.” It occupied over five acres and was referred to as a children’s paradise. A variety of amusements and entertainment were available. Included were a replica of the Canadian Rockies, a miniature railroad, mountain slide, Robinson Crusoe’s Beach, a pirate’s lair, boat rides and Noah’s Ark complete with animals.
See also 
- "Collier Quits Directorship of Exposition". Los Angeles Times. 1925-10-30. p. 2.
- "Exposition Head Retires". New York Times. 1926-05-26. p. 27.
- "Capt. Baker dead; head of Exposition". New York Times. 1926-06-06. p. 28.
- Kahn, Louis Isadore (1901-1974) - Philadelphia Architects and Buildings
- Proske, Beatrice Gilman, Brookgreen Gardens Sculpture, Brookgreen Gardens, SC, 1968 p. 150
- City of Philadelphia Information Locator Service entry
- "Sesquicentennial opens as sun shines; 100,000 pass gates". New York Times. 1926-06-01. p. 1.
|Wikimedia Commons has media related to: Sesquicentennial Exposition|
- Collection of Photographs from Sesquicentennial Exposition, PhillyHistory.org.
- Collection of artwork Postcards, Brochures, Photographs, related items from Sesquicentennial Exposition