[7] The Great Depression ruined the Stevens family, and the State of Illinois charged the hotel's owners with financial corruption.

In January 1944, the War Department closed a deal to sell the property for $4.91 million to a bricklayer turned private businessman named Stephen Healy.

[8] On December 7, 1944, delegates from 54 nations gathered in the Grand Ballroom of the Stevens Hotel to conclude and sign the Convention on International Civil Aviation, also known more popularly as the ‘Chicago Convention’, the defining international agreement which has since permitted the global civil aviation system to develop peacefully and in a manner benefiting all peoples and nations of the world.

As World War II drew to a close, Conrad Hilton purchased the hotel from Healy in February 1945.

[11] In April 1951, crowds gathered in the Great Hall to hear a speech by General Douglas MacArthur defending his conduct of the war in Korea, calling for a new American policy toward the conflict to replace the current "political vacuum".

[12] During the 1968 Democratic National Convention, the streets outside the Conrad Hilton Hotel were the scene of a police riot as antiwar demonstrators, being beaten and arrested, began to chant "The whole world is watching".

[4] In 2012 the hotel started a $150 million renovation, including new dining outlets 720 South Bar & Grill, SNAX and Kitty O'Sheas.

Refurbished in 2013, the suite includes 16-foot lake view windows, a baby grand piano, a billiard table, three balconies, three bedrooms on the lower level - each with multiple flat screen televisions, and a helipad.

[16] It has hosted famous guests such as Tony Blair, Jay Blunk, Frank Sinatra, John Travolta and Hu Jintao.