Since 1986, Don has represented a variety of corporations, partnerships and individuals in significant civil and commercial matters. In connection with his practice, he has been featured on CBS' 60 Minutes, CNN and The Phil Donahue Show. In 2004, Leading Lawyer Magazine named him one of Illinois’ "leading lawyers," a distinction earned by fewer than five percent of the state's lawyers.

In 1994, Don founded The Chicago Challenge – a non‑sectarian, tax‑exempt charitable and educational organization whose goal was to give some of Chicago’s most economically disadvantaged inner‑city children opportunities to realize their full potential. From 1994 until 2011, the Challenge helped to provide these children with quality education, healthcare, psychological counseling, after‑school tutoring, and extracurricular activities.

Don began practicing law in 1986 and became a partner in 1992. He has extensive experience in several practice areas including labor and employment, corporate reorganizations, bankruptcy and creditors' rights, and commercial litigation. He also has significant experience in a variety of industries including biotechnology, pharmaceutical, radiopharmaceutical, self-storage, consulting and automotive.

Since 1995, Don has overseen and managed significant litigation (including class action litigation) for several large corporate clients including a number of Firm anchor clients. The litigation has involved a wide variety of claims including contract, tort, RICO, consumer fraud and whistleblower retaliation pending in state and federal courts across the country, at both the trial court and appellate court levels, and in numerous arbitration proceedings.