sentences:  From 1983-1986, Block was an associate with the New York office of Skadden, Arps, Slate, Meagher & Flom, where his substantive areas of practice included constitutional claims involving Commerce Clause and Commercial Speech issues, financial services litigation, as well as merger and acquisition, securities, labor and administrative law litigation.From 1986 to 1990, Block was an attorney in the U.S. Department of Justice.Block started out as a litigation attorney in the Department’s Commercial Litigation Branch, and then from 1987–1990, Judge Block served as Senior Attorney-Advisor in the Office of Legal Policy and Policy Development, where he specialized in constitutional law, particularly in the areas of federalism, takings law, separation of powers, presidential power and foreign affairs issues.