During the Second World War, he served in the United States Army Air Forces (1943–1945), where he was a second lieutenant and pilot.

From 1961 to 1968, he was chairman of KTAR Broadcasting in Phoenix, Arizona, until it merged with a local billboard company to form Combined Communications Corporation.

His first diplomatic work was in the ceremonial role of Special Ambassador in 1972 at an independence celebration in Gabon, during the presidency of Richard Nixon.

In his resignation, Louis expressed optimism about the quality of relations with the United Kingdom and the government of Margaret Thatcher, yet stated his desire to return to corporate and philanthropic pursuits.

The building, which houses Northwestern's professional production and post-production facilities for the Department of Radio/Television/Film as well as public radio WNUR 89.3 FM and a classroom/lab for the Medill School of Journalism still exists on Northwestern's South end of campus today near Norris University Center.