He established his consulting practice in 1947 and headed it as president until he suffered a stroke in 1990.
Rich Simms, 36, Fitzgerald's senior vice president and media director, will head the new shop as president.
Bill Flynn, 47, was named to head the office as president.
He was educated in local schools and at Northwestern State University, an institution which he would head as president from 1934 to 1941.
Andy Fletcher, 42, will continue to head the agency as president and chief executive.
He succeeds Giovanni Magistrali, who will head the company's Italian operations as president and chief operating officer.
Tom Hall, currently president and executive creative director in the Chicago office, will head the office as president and chief executive.
Wes Bray, 45, one of four managing directors at Market Growth, will head the new unit as president.
From 1964-1966 Walker worked with a new publishing venture, the Negro Heritage Library, which he headed as president in 1966.
Nicos Nicopoulos, the chairman of Producta, will head the new agency as president.