[6] Lemann began his journalism career as a 17-year-old writer for an alternative weekly, the Vieux Carre Courier, in his home city of New Orleans.

Lemann won the 1980 Raymond Clapper Memorial Award "...for a series of stories outlining the plight of a family on welfare.

[9] During Lemann's time as dean, the Journalism School launched and completed its first capital fundraising campaign, added 20 members to its full-time faculty, built a student center, started its first new professional degree program since the 1930s, and launched initiatives in investigative reporting, digital journalism, executive leadership for news organizations, and other areas.

[11] In 2015, Lemann launched Columbia Global Reports, a university-funded publishing imprint that produces four to six ambitious works of journalism and analysis a year, each on a different underreported story in the world.

[13] Lemann is the author or editor of several books, including Transaction Man: The Rise of the Deal and the Decline of the American Dream (2019), Redemption: The Last Battle of the Civil War (2006); The Big Test: The Secret History of the American Meritocracy (1999); and The Promised Land: The Great Black Migration and How It Changed America (1991), which won several book prizes.