One of the five original clubs to form the USGA in the 1800s. Its original location was in Downers Grove, and then it moved west to Wheaton. The original track is now open to the public as Downers Grove Golf Club, and I highly recommend playing that course, it has a lot of old-school peculiarities.
Anyways, the current Chicago Golf Club in Wheaton is truly one of the very best golf courses in the world. It's wide open links-style and wide fairways, with thick fescue becoming penal if you miss the fairways. It's not long on the scorecard, but especially if you play from the tips, some holes can play really long. The wind is usually fairly tough, but rarely brutal.
Highly knowledgeable golfers have said that this course has the best greens in the world. The greens are huge and fast, with subtle breaks and lots of false fronts. Water only comes into play on two holes (9 and 10). To score great here, you really need to have your ball on the right level of the large, often multi-tiered greens.
Another author has written a full review here, with photos: top100golf.blogspot.com/….
If you ever happen to get an opportunity to play here, you absolutely have to take it. Truly one of the best courses in the world.