Mickelson was the force behind the development of Walter Cronkite and Fred Friendly as household names and pioneered several aspects of television news coverage, especially how cameras cover foreign and political events.
He died Friday night at Scripps-Mercy Hospital of complications from pneumonia, his widow, Elena, said Saturday. Mickelson had been living in San Diego and had been hospitalized since Monday.
Mickelson, who began working for CBS in 1943, was put in charge of news and public affairs at CBS Television in 1951, and soon CBS News' first "street reporter" was filming stories on location for the network's evening news. Don Hewitt, who went on to create 60 Minutes, produced and directed the spots.
"Sig was undoubtedly one of the pioneers of television news," Cronkite said. "Much of what we accomplished can be traced to his leadership in the founding days of this incredible medium."
Mickelson hired Friendly, a name synonymous with the birth of television news, to collaborate with Ed Murrow on See It Now, a television documentary series that went down in history for a piece that led to the downfall of anti-Communist Sen. Joseph McCarthy, R-Wis., in 1954, according to CBS News.
He helped arrange the first commercially sponsored television broadcast of a political event, the 1952 conventions, and tapped Washington, D.C. newsman Cronkite to anchor the broadcasts.
"It is for his selection of Walter Cronkite that Sig will be remembered forever," said Hewitt, who directed coverage of the conventions.
By tapping the likes of Cronkite and Friendly, Mickelson created the television news "anchorman," who gathered material on-air from other reporters.
In 1953, Mickelson oversaw the first same-day U.S. broadcast of a foreign event with the coronation of Queen Elizabeth II and went on to help expand the network's international camera crew and international coverage.
He became the first president of a national network news division with the creation of CBS News Division in 1959. He supervised the full broadcast of the 1960 Olympic games before leaving CBS in 1961 to lead the international broadcast division of Time, Inc.
He taught at Northwestern University, San Diego State University and Louisiana State University, where he served as the Manship Professor of Journalism from 1991 to 1993. He wrote seven books, including The Decade that Shaped Television News published in 1998.
Mickelson was born in Clinton, Minn., and got his master's degree from the University of Minnesota. His first CBS job was at the Minneapolis radio station in WCCO.
He reported from political conventions for CBS Radio in 1948 and was called to New York headquarters in 1949. He founded the Radio and Television News Directors Association and was president from 1948 to 199.
Mickelson's first wife, Mabel Brown, preceded him in death in 1985. He remarried in 1986 and is survived by his widow, two children from his first marriage, two stepchildren and seven grandchildren.
Funeral arrangements were pending.