One of my favorite bookshops is Milwaukee's Harry W. Schwartz on Downer Avenue. When I was a young man just trying to get by on the streets of Milwaukee (much like now except I'm not so young anymore) I would frequent the Harry W. Schwartz store downtown. That is the bookshop I knew and loved in those days. It took up the first floor of the Iron Block building at the corner of Water & Wisconsin. In 1997 Harry W. Schwartz moved out of that downtown location and up to its current Downer Avenue spot on the East Side. In doing so, Schwartz returned to its Downer Avenue roots. There are now several Harry W. Schwartz bookshops in the Milwaukee area. I've been in one or two of the newer ones, and I admit they feel a bit too "suburban" for my taste. But the Downer Avenue store remains an important aspect of the literary East Side culture.
You may find the Schwartz web site here.
In particular, I encourage you to read the brief account of the history of the company here, and if you do, you will find an interesting connection between Milwaukee and my second favorite city, New Orleans.
Finally, the Downer Avenue shop has its own blog, which I commend to you. This, of course, is not to say I would endorse everything one may find there. I always support enterprises, however, which help open the mind to the literary landscape available to us.