Construction began in 2019 on the 73-storey concrete structure designed with a glass facade.
The original plan was for a 832-building, but restrictions forced Time Equities, Inc, JK Equities and Oak Capitals, to reduce the height.
McHugh Construction drove caissons 87 feet to reach bedrock at the site and according to the developers, the building will have the tallest observation deck in Chicago.
Jahn was born in Germany in 1940 and moved to Chicago in 1966. He died in 2021.