He's homeless and in dire need of a heart transplant yet, this disabled veteran is determined to make a difference. And to do it, he's driving his wheelchair across the country. But as Eyewitness News Reporter Kim Carapucci explains, he's taking it one mile at a time.

Crossing a busy street in Valdosta, David Whittaker is a thousand miles closer to crossing the country on his wheelchair.

"The doctors don't think I can make it, so I'm gonna prove that I can make it," said Whittaker.

He's only 53 years old, but David's heart is failing. In fact, he's died on two different occasions, and yet, he can't get the help he needs.

"I'll remember these words forever. She said, 'Mr. Whittaker, we understand you need a heart transplant, but a heart's a very precious thing and we can't just give a heart to anybody and we can't give you a heart. You're homeless,'" said Whittaker.

It was then David decided he didn't want any other homeless veteran to go through what he has.

"I take it one mile at a time. One mile at a time. I never know what lies ahead," said Whittaker.

And now, he's taking a five thousand mile trip from Florida to Washington to raise awareness.

"I don't want people to feel sorry for me. I'm out here because I want to be out here," said Whittaker.

David knows it's dangerous and his health is deteriorating , but he's determined to leave a legacy.

"If I'm going to die from this heart that I've got, I wanna go out making a difference," said Whittaker.

For more information about David Whittaker's mission to help homeless veterans, visit www.hhva.veterancottages.org. Whittaker is being tracked by GPS and guests can find out where he is by visiting that website.