Now, of course "tallest person ever" is shorthand; what is generally meant by that phrase is "tallest person ever for whom there is indisputable evidence." It's certainly possible that someone in human history, someone more distant from us than Mr. Wadlow, who was born in 1918, when science existed and things could be described as indisputable in a way that we accept as indisputable in 2016, got to be taller than 8'11.1". Certainly many people have claimed, or have been claimed, to be taller than that. Sideshow performers were regularly billed as much taller than they actually were, like ten feet tall, which sounds ludicrous until you look at a family picture of the Wadlows:
(Click through for lots more pictures and info about Robert Wadlow.)
My mind is inclined to reject that image even though it's just a photograph. If I were to see Robert in person, without the nongiant people around him for scale, you could slap any number on him and I'd be inclined to believe it. He's eight feet tall, he's ten feet tall, he's twelve feet tall -- whatever height he is, it's too great for my mind to accept from way down here, so sure, why not?
Robert Wadlow was seven feet tall when he was my nephew's age and his parents got lots of offers to exhibit him as a freak, which they turned down. Robert didn't like the idea either, and when during the Great Depression he finally agreed to appear in the Barnum and Bailey Circus, he did so only on the conditions that he'd appear in the center ring, not the sideshow, wearing an ordinary suit (to the extent, of course, that any of his suits were ordinary). His long-term plan was to go to law school. When he died, at only twenty-two, his parents had his ten-foot steel coffin sealed under concrete so no one could dig up his body in order to exhibit his skeleton. (The second-tallest person ever, John Rogan, was also buried under concrete. Their families may have been thinking of poor Charles Byrne, an eighteenth-century Irish giant reportedly so obsessed with the idea that doctors would hack open his corpse that he ordered himself buried at sea in a lead-lined coffin -- but all to no avail, as a doctor bought the corpse and boiled it to get at the skeleton, which I believe is still on display at the Royal College of Surgeons, despite some public pressure to belatedly respect Byrne's wishes.) I don't think physically unusual people who choose to exhibit themselves for money are in any way inferior to those who don't, but I like that Robert's parents enforced his wishes not to be a sideshow attraction when he was no longer able to. Love can take many forms, and sometimes love is a really thick layer of concrete.