Chicago probably represents about 90% of it. Black on Black crime skew the results.
The persistence of this myth is laughable—in no small part because it's a fiction designed to drive an NRA narrative that any gun regulation is a bad, senseless, ineffectual regulation, holding up Chicago as
Exhibit A. New York used to play the same role in the national consciousness—of the evil liberal empire's effective capital—until 9/11 hit and suddenly NYC was America's bleeding heart.
For the year in question in that chart (2015), Chicago is all the way down at #25 for murder rates in cities with 100,000+ population. (And
here is another link for fun that breaks down cities even further by population boundaries.)
St Louis, Baltimore, Detroit, New Orleans, and Birmingham were the "top" five, and, from your state, Milwaukee rounded out the top-ten at #10. FearlessLeader would be glad to know Savannah was #13 that year; Atlanta, too, was higher than Chicago, at #19.
Violent crime in Chicago is highly localized; it's sad, it's a problem, and I'm by no means dismissing it. However, if you're looking for the most violent, dangerous cities in the US, you have to look pretty far down the list to find Chicago—and there are quite a few down in that deep-red gun-lax south (which the NRA would rather not talk about).