John Hancock Center

The project, which would become the world's second tallest building at opening, was conceived and owned by Jerry Wolman in late 1964. The project was financed by John Hancock Mutual Life Insurance Company. Construction of the tower was interrupted in 1967 due to a flaw in an innovative engineering method used to pour concrete in stages, that was discovered when the building was 20 stories high.[15] The engineers were getting the same soil settlements for the 20 stories that had been built as what they had expected for the entire 99 stories. This forced the owner to stop development until the engineering problem could be resolved, resulting in a credit crunch. The situation is similar to the one faced during the construction of 111 West Wacker, then known as the Waterview Tower. Wolman's bankruptcy resulted in John Hancock taking over the project, which retained the original design, architect, engineer, and main contractor.

The building's first resident was Ray Heckla, the original building engineer, responsible for the residential floors from 44 to 92. Heckla moved his family in April 1969, before the building was completed.

The 1988 film Poltergeist III was set at the John Hancock Center and was filmed in early 1987.[16]

On December 10, 2006, the non-residential portion of the building was sold by San Francisco-based Shorenstein Properties for $385 million and was purchased by a joint venture of Chicago-based Golub & Company and the Whitehall Street Real Estate Funds.[17] Shorenstein Properties had bought the building in 1998 for $220 million.

Golub defaulted on its debt and the building was acquired in 2012 by Deutsche Bank, who subsequently carved up the building.[18] The venture of Deutsche Bank and New York-based NorthStar Realty Finance paid an estimated $325 million for debt on 875 North Michigan Avenue in 2012 after Shorenstein Properties defaulted on $400 million in loans.[19] The observation deck was sold to Paris-based Montparnasse 56 Group for between $35 million and $45 million in July 2012.[20] That same month, Prudential Real Estate Investors acquired the retail and restaurant space for almost $142 million.[21] In November 2012, Boston-based American Tower Corp affiliate paid $70 million for the antennas.[22] In June 2013, a venture of Chicago-based real estate investment firm Hearn Co., New York-based investment firm Mount Kellett Capital Management L.P. and San Antonio-based developer Lynd Co. closed on the expected acquisition of 875 North Michigan Avenue's 856,000 square feet (79,500 m²) of office space and 710-car parking deck. The Chicago firm did not disclose a price, but sources said it was about $145 million.[19] This was the last step in that piecemeal sale process.[19] In May 2016, Hearn Co. announced that they were seeking buyers for the naming rights with possible signage rights for the building.[23]

Hustle up the Hancock is an annual stair climb race up the 94 floors from the Michigan Avenue level to the observation deck. It is held on the last Sunday of February. The climb benefits Respiratory Health Association. The record time as of 2007 is 9 minutes 30 seconds.

The building is home to the transmitter of Univision's WGBO-DT (channel 66), while all other full-power television stations in Chicago broadcast from Willis Tower. The City Colleges of Chicago's WYCC (channel 20) transmitted from the building until November 2017, when it departed the air as part of the 2016 FCC spectrum auction, and will eventually return as a part of WTTW's spectrum from Willis Tower.

On February 12, 2018, John Hancock Insurance requested that its name and logos throughout the building's interior be removed immediately; John Hancock had not had a naming-rights deal with the skyscraper's owners since 2013. The building's name was subsequently changed to its street address as 875 North Michigan Avenue.[24]

On November 11, 1981, Veterans Day, high-rise firefighting and rescue advocate Dan Goodwin, for the purpose of calling attention to the inability to rescue people trapped in the upper floors of skyscrapers, successfully climbed the building's exterior wall. Wearing a wetsuit and using a climbing device that enabled him to ascend the I-beams on the building's side, Goodwin battled repeated attempts by the Chicago Fire Department to knock him off. Fire Commissioner William Blair ordered Chicago firemen to stop Goodwin by directing a fully engaged fire hose at him and by blasting fire axes through nearby glass from the inside. Fearing for Goodwin's life, Mayor Jane Byrne intervened and allowed him to continue to the top.[25][26]

On December 18, 1997, comedian Chris Farley was found dead in his apartment on the 60th floor of the building.[27][28]

On March 9, 2002, part of a scaffold fell 43 stories after being torn loose by wind gusts around 60 mph (100 km/h) crushing several cars, killing three people in two of them. The remaining part of the stage swung back-and-forth in the gusts repeatedly slamming against the building, damaging cladding panels, breaking windows, and sending pieces onto the street below.

On November 21, 2015, a fire broke out in an apartment on the 50th floor of the building. The Chicago Fire Department was able to extinguish the fire after an hour and a half; five people suffered minor injuries.[29]

On February 11, 2018, a fire in a car on the seventh floor required approximately 150 firefighters to extinguish.[30]

On November 16, 2018, an express elevator cable broke. Initial reports stated that an elevator with six passengers plunged 84 stories from the 95th to 11th floor. Since express elevators are not accessible from floors within the express zone, a team of firefighters had to break through a brick wall from the parking garage to extricate the passengers, none of whom suffered injuries. Elevators to the 95th/96th floor were closed thereafter pending investigation.[31] Subsequent investigation documented only a controlled descent from the 20th floor to the 11th floor.[32]

A piece of cladding fell from the building on January 5, 2022.[33]

Located on the 94th floor, 360 Chicago Observation Deck is 875 North Michigan Avenue's horizon observatory. The floor of the observatory is 1,030 feet (310 m) off of street-level below. The entrance can be found on the concourse level of 875 North Michigan Avenue, accessible from the Michigan Avenue side of the building. The observatory, previously named John Hancock Observatory, has been independently owned and operated since 2014 by the Montparnasse 56 Group of Paris, France.[40] The elevators are credited as the fastest in the Western Hemisphere, with a top speed of 1,800 ft/min (20.5 mph).[41] The observatory boasts more floor space than its direct competitor, Skydeck at the Willis Tower. There is a full bar called BAR 94 which stocks local beer and spirits from Revolution Brewing and KOVAL Distillery.[42] In the summer of 2014, 360 Chicago added its TILT attraction. TILT, for an additional fee, is a series of floor-to-ceiling windows that slowly tilt outside the building to 30°.[43] The platform is on the observatory level, and faces south over the city.

Separate from its observatory, 875 North Michigan Avenue has a restaurant on its 95th floor named the Signature Room, with an accompanying bar on the 96th floor called the Signature Lounge.[44]