Robert Pershing Wadlow also known as the Alton Giant and the Giant of Illinois, is the tallest person in history for whom there is irrefutable evidence. The Alton and Illinois monikers reflect the fact that he was born and grew up in Alton, Illinois. Wadlow reached 8 ft 11.1 in in height and weighed 439 lb at his death at age 22. His great size and his continued growth in adulthood were due to hyperplasia of his pituitary gland, which results in an abnormally high level of human growth hormone. He showed no indication of an end to his growth even at the time of his death. 

February 22nd, 1918 in Alton  /  Died:   Jul 15th, 1940 - aged 22