A lot of out-of-town firms have come to the Valley seeking the same thing: booming corporate and intellectual property practices tied to the tech sector.

Sidley Austin is one of just a handful of firms that can claim to have succeeded. The Chicago-based firm opened its Palo Alto office with three lateral partners in 2009 and today has more than 40 there, plus nine more who work from both the Valley and S.F. offices.