Complex sentence: He left private practice in 1981 to be Chief Counsel for the U.S. Government Printing Office until 1983 when he became the Chief Counsel for the U.S. Maritime Administration for two years.
Split into simpler sentences: He left private practice in 1981 to be Chief Counsel for the U.S. Government Printing Office. He served in that role until 1983, when he became the Chief Counsel for the U.S. Maritime Administration for the next two years.