Robert Pershing Wadlow (February 22, 1918 – July 15, 1940), also known as the Alton Giant and the Giant of Illinois, was an American man who was the tallest person in recorded history for whom there is irrefutable evidence.

Wadlow’s height was 8 ft 11 in (2.72 m) while his weight reached 439 lb (199 kg) at his death at age 22. His great size and his continued growth in adulthood were due to hypertrophy of his pituitary gland, which results in an abnormally high level of human growth hormone (HGH). Even by the time of his death, there was no indication that his growth had ended. [source]

The oldest of five children, Robert entered the world no differently to most babies. He was born on 22 February 1918 to two regular-sized parents, weighing an unremarkable 3.85 kg (8.7 lb). In this family portrait taken circa 1935, you can get a sense for just how tall Wadlow was.

There are plenty more photos and stories online of Wadlow’s life. You can start on Wikipedia and Guinness World Records and go from there.