Nik Wallenda nears the middle of his tightrope walk over Niagara Falls as seen from Niagara Falls, Ontario, on Friday, June 15, 2012. Wallenda has finished his attempt to become the first person to walk on a tightrope 1,800 feet across the mist-fogged brink of roaring Niagara Falls.

Tens of thousands of people gathered at the falls June 15, 2012 and millions more were believed to be watching on television as Wallenda crossed some 200 feet in the air on a two-inch-wide wire strung over the raging waters of Horseshoe Falls, the largest of the three falls that make up Niagara Falls.

The seventh-generation member of the famed Flying Wallendas had long dreamed of pulling off the stunt, never before attempted.

Wallenda braved the winds and heavy spray in his historic feat. Wallenda trotted in his final steps across the wire and stepped into Canada, barely 25 minutes after he started.

After he greeted his wife and family, Wallenda was approached by customs agents, who asked him for his passport, which he presented. "No, I'm not carrying anything over. I promise," he said. "What is the purpose of your trip sir?" the agent asked. "To inspire people around the world," Wallenda said.

Wallenda said the mist and the winds midway across the walk were the biggest challenge. "It's all about the concentration, the focus, and it all goes back to the training," he said. "I'm grinning from ear to ear because I can see I'm here. I made it," he added.

Others have crossed the Niagara River itself, but never over the falls. Wallenda said that Friday June 15, 2012 feat will be the fulfillment of a lifelong dream as well as a chance to honor his great-grandfather, legendary funambilist Karl Wallenda, who died after falling from a tightrope in Puerto Rico in 1978.

Wallenda, 33, has called his great-grandfather his "biggest inspiration" and said he would be thinking of him during the stunt. The 1,500-foot walk between Goat Island in the U.S. side to Table Rock in Canada was fraught with unforgiving natural conditions: blinding mist and drafts created by the force of the waterfalls crashing down on the Niagara River.

As for Wallenda's next megastunt, he already has the permits to become the first man to ever walk a wire across the Grand Canyon.