About 25 years ago, I read a book called Presidential Courage by John B. Moses, M.D. and Wilbur Cross. It was a fascinating history of our nation’s chief executives, written from a medical point of view.

In addition to the familiar stories of Woodrow Wilson’s stroke, Franklin Roosevelt’s paralysis, Dwight Eisenhower’s heart attack and John Kennedy’s back problems, the book chronicled such lesser-known medical episodes as Grover Cleveland’s secret surgery for cancer (kept secret lest word of the President’s illness worsen the financial panic that gripped the country in 1893), and the lung abscess that plagued Andrew Jackson for the rest of his life after a duel in 1806 left him with a bullet embedded in his chest.

The chapter on Abraham Lincoln was particularly interesting. When Lincoln was ten, he was kicked in the forehead by a horse. There was no diagnosis at the time, because he appeared not to have been seriously injured. But medical opinion today holds that his skull was probably fractured on the point of impact, deeply enough to cause brain damage. This was probably the cause of the severe vision problems Lincoln experienced in later life, and may have contributed to his recurring bouts of chronic depression.

The authors also argued that Lincoln was afflicted with “Marfan’s syndrome”, a rare genetic heart disease for which there still is no cure. Further, they explored the little-known fact that Lincoln was suffering from smallpox when he wrote and delivered the Gettysburg Address in 1863 –- which may have contributed to the brevity and tone of his most famous speech.

Whether or not Lincoln had Marfan’s syndrome –- which would have killed him within a year, had he not died at the hands of John Wilkes Booth –- is still being debated by medical experts. But the smallpox diagnosis was confirmed just last month in an article published by two researchers at the University of Texas Medical Branch at Galveston.

A few days before Lincoln left for Gettysburg, his son, Tad, was confined to bed with a high temperature. The doctor had misdiagnosed Tad’s illness as scarlet fever. Actually, it was smallpox, and when Lincoln left for Gettysburg, he carried the same disease in its incubation period.

On the trip back to Washington, immediately after giving his speech, Lincoln was seized by a severe headache, violent sweats and utter exhaustion. As there is no evidence that Lincoln was ever immunized against smallpox, there was at least a 30 percent chance that he could have died, according to Dr. Armond S. Goldman, the lead author of the UTMB study. Fortunately, he recovered, and was able to return to work about three weeks later.

Even in the shadow of a potentially fatal illness, however, Lincoln retained the saving humor that sustained him through even the darkest days of the Civil War. When his doctor told him he had smallpox, Lincoln asked him if he had passed through the White House waiting room on his way in.

Yes, replied the doctor, and he noted that it was jammed with people.

“It’s always full of people,” said Lincoln. “Do you have any idea what they are there for?”

“Perhaps I could guess,” ventured the doctor.

“Yes, Lincoln quipped, “they are there, every mother’s son of them, for one purpose only: namely, to get something from me. For once in my life as President, I find myself in a position to give everybody something!"