From your photo, it looks like an ash tree, but it's not close enough to tell. Other possibility is a hickory maybe? Same with the disease issue. Too hard to tell from the photo. But, if it is an ash tree, it's probably Ash Anthracnose. It's warm and very wet in Chicago this year, right? Perfect conditions for this: "Ash anthracnose is probably the most common disease of green ash. It is caused by a fungus and occurs during cool, rainy weather. It can be confused with ash plant bug and herbicide damage. Individual trees vary in their susceptibility to anthracnose to the extent that some trees may be infected every year and others only rarely or never at all. Initial symptoms on green ash include very small (grain of sand-sized) purple or brown spots, sometimes with a cream-colored center, on young leaves. These spots may enlarge and coalesce forming brown blotches. Leaves often become distorted and drop and young shoots may be killed. Defoliation and leaf browning cause homeowners a great deal of concern, but treatment is generally not warranted. Affected trees usually put out a second flush of leaves and make up for lost time later in the growing season. However, trees that have been defoliated three to five years in a row might benefit from chlorothalonil, mancozeb or thiophanate treatment at budbreak to prevent infection. The fungus can overwinter on the ground in infected leaves and twigs, so raking and disposing infected material may help reduce infection the following spring." Your main link didn't work for me -- brought up a screen, but no photos, looks like you have to create an account to view them, and I didn't want to do that. Here is a link that might be useful: Pamphlet where I got the Ash Anthracnose info:

I'm very surprised they haven't done something about the RRD as they have a large, knowledgeable group of volunteers out there. Josh, your pictures are gorgeous thank you for showing us; they've done a remarkable job out there, haven't they? ogrose

Then, that is where you want to plant the heat lovers. Those plants which flourish with all the heat you can provide. Work with the conditions instead of fighting them continually. Fix what you can then make use of the conditions you've been dealt. You and the plants will be significantly happier. I know the very front of my yard is going to remain dry, sun baked and higher heat than the remainder of the yard. It's bordering on the public street and sidewalk and will have a rock "mulch", so the full southern exposure is certain to be hotter than anywhere else I intend to plant. So, in that heat strip is where the dry loving, heat dwellers will go. I will reserve the water for those areas I can more easily grow roses and other plants desiring more moderation.

I had 3 roses left in South Carolina, after being neglected, hit with lawn mowers/weed eaters, and never even watered in at least 2 years. Sea foam, Caldwell Pink, and a tiny Belinda's Dream that I found searching around the yard. I caught it as it was growing back from being cut, and moved it here. When I moved it, I was hoping it was Easy Does it. I already have two BD, but it got saved anyway, and looks so happy. The funny thing is, roses are doing better for me here in a colder zone, and the only difference besides zone, is hubby isn't here all the time. I keep rubbing it in on him when he says how nice they look - "yeah ... that's the result of not being mowed down in cold blood" lol Well I did neglect them more in SC though, I got tired of fighting the fire ants. Not going to tell him that, because I don't want him near them. ;-)