That fact came to light after the family of a World War II hero donated some of his belongings to the Pritzker Military Library.
Currently, among the many displays at the institution is the Class A uniform of Major General William Levine, who is one of the highest ranking Jewish Generals in US Army history. Levine was among the allied liberators of the death camp at Dachau.
General Levine passed away this year, and his family donated his uniform, papers and a handgun that he had obtained from a Nazi officer.
"We realized when we received that gift that we couldn't keep that gun in the city of Chicago," said Ken Clarke, Pritzker Military Library CEO.
The Chicago Firearms Ordinance permits handgun possession in the home, but there's nothing in its wording that would allow museums to display unloaded firearms.
General Levine's handgun, which is a Walther PP, and other Pritzker firearm collection pieces are kept in a safe at a gun range in west suburban Lombard where they are legal- but seldom seen.
A proposed museum exemption has the support of the council's most powerful alderman. Alderman Ed Burke has introduced an ordinance that would permit Chicago museums to display unloaded firearms as curios or relics.
"One would think this is an anomaly- that it was an unintended consequence of a well-intentioned law that ought to be corrected," said Burke.
"It's important to be able to show things that were part of his life and who he was," said Kat Latham, Pritzker Military Library collections manager.
The library says it sees this handgun in historical terms- as an extension of a general's life story that the public should be able to see in full. As for the notion that someone might target a displayed firearm for theft- administration believes it is not a likely possibility.
"If somehow they're able to get past the locked door, the motion sensors, the alarms, then they'd get to a case that would be very hard to get into," said Latham.
A case with bulletproof glass- just like the one that protects Congressional medals of honor- is sure to serve as a deterrent, organizers say.