For several years, he held the certified Guinness World Record for the most hours on commercial network television before being surpassed by Regis Philbin, who died 24 days after he did.

[7] Downs started his career in radio in 1939 and began in live television in 1945 in Chicago, where he became a regular on several nationally broadcast programs over the next decade.

Downs served in the United States Army during World War II in 1943 and then joined the NBC radio network at WMAQ as an announcer in Chicago, where he lived until 1954.

[12] He can be heard announcing the ground breaking 1948–1950 radio show Destination Freedom (written by Richard Durham) which told stories of historical and current Black people.

[15] Downs made his first television news broadcast in September 1945 from the still-experimental studio of WBKB-TV (now WBBM-TV) in Chicago, a station then owned by the Balaban and Katz theater subsidiary of Paramount Pictures.

He also announced the Burr Tillstrom children's show Kukla, Fran and Ollie from the NBC studios at Chicago's Merchandise Mart after the network picked up the program from WBKB.

In March 1954, Downs moved to New York City to accept a position as announcer for Pat Weaver's The Home Show starring Arlene Francis.

[6] He also hosted NBC's Today Show for nine years from September 1962 to October 1971 and co-hosted the syndicated television program Not for Women Only with Barbara Walters in 1975–76.

[20] Downs earned a postgraduate degree in gerontology from Hunter College while he was hosting Over Easy, a PBS television program about aging that aired from 1977 to 1983.

[33][34] As part of Arizona's centennial celebration in February 2012, Downs narrated Aaron Copland's Lincoln Portrait on stage with the Phoenix Symphony.

[38] Downs held a private pilot certificate, and was rated for multi-engine airplanes, single-engine seaplanes, hot air balloons, and glider aerotow.