Wallenda wore a waterproof outfit and suede-soled slippers especially designed by his mother. Powerful TV lights focused on him the whole way, as millions of people around the world followed the event on television.
The acrobat had a two-way radio and and a small earpiece, and was able to communicate with his father, identified by ABC as Terry Troffer.
"My God, it's incredible, it's breathtaking," Wallenda said soon after starting his quest.
He later reported being "very wet."
"This is so physical, not only mental but physical," Wallenda said. "Fighting the wind isn't easy. I feel my hands are going numb."
Wallenda's father gave him words of encouragement throughout the walk.
"You're doing good. Take your time," said Troffer, whom ABC described as the event safety coordinator.
The crowd went wild when Wallenda reached the Canadian side of the Falls.
Still on the high wire, Wallenda kneeled briefly on the cable and waved to the roaring crowd.
At ABC's insistence, Wallenda was attached to a harness that would have allowed him to climb back onto the high wire if he slipped and fell.