Our thirty-second president, Franklin Delano Roosevelt, appeared on dozens of magazine covers. In my research on his health for a propective book, these magazines were very helpful.
Roosevelt probably had and died of Melanoma, a highly malignant tumor almost always fatal, which began over his left eyebrow. It is first seen in 1923 on the cover of TIME and its evolution into a lesion with characteristics resembling Melanoma and then mysteriously disappearing can be well documented chronologically using magazine covers.
Roosevelt also had a penchant for secrecy. All "official " press photos were edited and even retouched. The magazine photos were less apt to be altered, hence there value as historical documents.
This month, April 2008, in Archives of Dermatology is my article co-authored with one of the world's leading dermatopathologists, providing a more detailed explanation of some of the photos above. See the review at History News Network at http://hnn.us/roundup/entries/49481.html