Early life
His interest in photography came after his older brother got a Leica camera. He then built his own camera from scratch.
 At National Geographic
As a staff member of National Geographic magazine, Abercrombie was known for his work in Arab countries, visited all seven continents, and was one of the first two journalists to reach the South Pole in 1957 (the other was Rolla J. "Bud" Crick of the Oregon Journal). Abercrombie was the first person to win both the Newspaper Photographer of the year (1954) and the magazine photographer of the year (1959). He dived with Jacques Cousteau who said it "was like swimming with a fish".
After 1965 Abercrombie frequently covered Saudi Arabia and he converted to the Muslim faith, taking the name Omar. He was the magazine's expert on the Middle East, and reported from Mecca. He covered the region from Morocco to Afghanistan for more than three decades, until he retired in 1994.
After retiring from National Geographic in 1993, Abercrombie taught geography at George Washington University.
Abercrombie died at Johns Hopkins Hospital of complications from open-heart surgery.
Abercrombie's photojournalism career is documented in the 2004 film, White Tiger: The Adventures of Thomas J. Abercrombie, by filmmaker Patricia A. Leone, Blue Marlin Productions, Progressive IMG and Gabriel Film Group with original music score by Kevin Harkins. The film showed at the New York International Independent Film and Video Festival.
Abercrombie is also one of four pioneering photographers to be honored in Odysseys and Photographs book published by the National Geographic Society, along with an exhibition at the National Geographic Museum in Washington, D.C. and in London.