From 1966 to 1969, Lewis served in the U.S. Peace Corps as associate director in Nigeria and later as country director in Uganda. On his return from Africa, he was named director of the Peace Corps' East and Southern Africa Division. After rising through the ranks of C&P Telephone in Washington, D.C., to become president and CEO, in 1994 he became CEO of National Public Radio.
Lewis retired from NPR in 1998, and one year later was appointed by President Clinton as U.S. ambassador to South Africa. For his service to humanity, Lewis in 1994 received the Distinguished Service Citation, the highest honor bestowed by the University and the Alumni Association. He currently serves as a vice chair of the national alumni board of directors.
Lewis is a member of Alpha Phi Alpha, the first intercollegiate Greek-letter fraternity established for African Americans.
His son is actor Phill Lewis.