Research into the building at 100W Grand (currently the location of Fado) is turning out to be pretty tricky.
We know that in the 1980s, it was the Conklin and Adler law firm.
However, it gets a bit hard to trace before that. I'm almost certain that Conklin and Adler were the first to use 100W Grand as the address; prior to that, the entrance was almost certainly on Clark. My guess is that C&A didn't want to be associated with Clark; they probably moved in at a time not so very long ago when that stretch of Clark was just one strip club after another.
Rumor has it that Clarence Darrow once had an office in the building; we know he had one in the Rookery and one at 94 LaSalle (which, since the 1909 renumbering, would have been half a block down from this building), but I haven't been able to verify that yet.
We do have some pretty good information on the place, but the number of address changes at this place make it hard to verify things.
Anyone know any more than I do? Send the info along!