NASHVILLE, Tennessee (AP) – You'd think after ten years, comedians Jeff Foxworthy, Bill Engvall and Larry the Cable Guy would be tired of each other's jokes.

They started Blue Collar Comedy in 2000 with comedian Ron White, hitting the road for what was supposed to be a four-month tour.

The tour worked so well and there was such a demand to see it that four months turned into three and a half years, three movies, more touring and a TV show.

The franchise has sold more than 9.5 million DVDs since its debut in 2003.

"I don't think we had any idea how successful it was going to be," said Engvall.

Larry the Cable Guy – wearing his trademark sleeveless flannel shirt and camouflage hat – joked that he didn't quit his day job when Foxworthy first called him about doing the Blue Collar Comedy Tour.

"I remember when I got on it, and I said, 'Well, it should last a couple years, Foxworthy's involved with it'. But I kept my job at Radio Shack.

I was assistant manager down there, only because I knew where the batteries were," he said. "No, you know what, I don't think any of us ever dreamed it would last that long, but it did and people still love it."

Now they're celebrating the ten-year anniversary of Blue Collar Comedy with a special on CMT.

In between taping promos, Foxworthy, Engvall and Larry the Cable Guy cracked each other up with impromptu stories and antics you'd expect to see during the finale of a Blue Collar Comedy show.

Their obvious friendship is a key factor in their success.

"When you're a comic, if you do your job right you don't laugh, you keep a straight face," said Foxworthy of their signature finales when they would bring out stools and improvise together on stage. "I think that was the appeal of it, that (the audience) kind of got to see us with our guards down, making each other laugh."

"To be able to tour with three of your best friends, have a great time and people pay money to hear what we have to talk about, I love America," said Engvall.

Foxworthy wrote his first joke about rednecks, a derogatory term for a backward person usually from the American South, in 1986 and started doing page-a-day calendars in 1990.

After all this time, he said he isn't worried about running out of material.