Three days a week, 91-year-old Ernie Andrus puts on his support stockings and tennis shoes, gently lowers himself out of the RV he's been living in, and slowly returns to his mission.

"The older I get, the slower I go," said Andrus.

Andrus will become the oldest person in America to run across America.

Ernie Andrus CBS News

"I'm running the whole thing, every step of the way," Andrus told CBS News.

He began in 2013 near San Diego. When we met him last summer he was outside Phoenix.

Andrus obviously loves running, but the World War II veteran says there's another, much greater purpose here.

"You want people to know what the war was all about, and what it took to win it," said Andrus.

Specifically, this old sailor is running to raise awareness for one of the unsung heroes of the war -- a ship he served on called an LST. It stands for "Landing Ship, Tank" and it's how the Allies got heavy equipment onto beaches.

Andrus is running to raise awareness for one of the unsung heroes of WWII -- a ship he served on. CBS News

The U.S. built more than a thousand LSTs during the war, but today only one remains in its original configuration. It's parked on the Ohio River in Evansville, Indiana. And Andrus says if he can run across the country at 91, the least you can do is drive to Indiana to see the thing.

"This shouldn't be forgotten. Eisenhower and Churchill both made a similar remark that it's the ship that won the war. ... Without 'em how could you have taken all those islands? How could you have even taken Normandy?" Andrus said.

Which is why, 70 years later, Andrus is out here returning the favor. He runs five miles, gets a ride or hitchhikes back to his vehicle, and then runs another five, two days later.

"If you fail, you're a crazy old man. If you succeed, you're a hero," said Andrus.

After our first story on Andrus aired, I was leaning towards crazy old man. But we found him in Waco, Texas surrounded by supporters who join him on occasion.

"I'm making so many friends," said Andrus. "I'm loving it."

Next stop -- the Atlantic Ocean, still a monumental goal, but with nearly two-thirds of the run now behind him, this old Navy man is gaining an army of believers.

To contact On the Road, or to send us a story idea, email us.