Robert Pershing Wadlow (1918–1940)   He looked like a stilt-walker, or a suited sunflower, parading his head along the tidy streets of Alton. His aerial ears stopped cars.   Illinois’s tallest boy—his height: eight feet and eleven inches. He occupied a sweeter air, above the strangers’ cologne and second-lung smoke, the cheesy pong of spongy sandwiches.   Wherever he’d go, an impromptu camp would form: upturned faces lengthening with surprise. The suck and pop of gasps as he waded through the paddling pool of people.   Handshakes were ribbon-cutting protocol; his foot-long hands englobed other folks’. They were useless with…