Abraham Lincoln. Portrait of Abraham Lincoln (1809-1865), 16th president of the USA and a sufferer of Marfan's syndrome. Marfan's syndrome is a hereditary disorder characterized by excessive tallness, long slender fingers and heart defects. Lincoln's leaness, thin head and sunken breast were because of his condition. Lincoln is best known as the president who led his country through the Civil War (1861-1865) and who liberated the southern slaves. He was assassinated by the actor John Wilkes Booth whilst at the theatre.