One of television's greatest actors has passed away.

James Arness, star of the Western series Gunsmoke has died. He was 88.

Jim passed away this morning at home with his wife of natural causes. He went quietly in his sleep, Arness' rep, Ginny Fazer told

In Gunsmoke Arness played the role of Marshal Matt Dillion, who watched over the town of Dodge City and kept the bad guys away.

The show, which was a weekly drama, ended in 1975. After the show was over, Arness reprised his role in five made-for-TV movies spanning from 1987 to 1994.

Arness was a World War II veteran from Minnesota. He received the Purple Heart.

He first began his acting career in 1947 in the film The Farmer's Daughter, opposite Loretta Young. He also appeared in John Wayne movies including Hondo and Big Jim McLain. He also played the creature in the horror film The Thing From Another World which was released in 1955.

He was retired and very much enjoying the time with his family. He was a very devoted family man, Fazer said. The funeral will be private, family only. And they have asked that in lieu of flowers or anything else, donations be made in Jim's name to their favorite charity, United Cerebral Palsy.

Arness had left a farewell letter to his fans on his official website in the case he passed away.

I had a wonderful life and was blessed with some many loving people and great friends. The best part of my life was my family, especially my wife Jane, he wrote. I wanted to take this time to thank all of you for the many years of being a fan of Gunsmoke, The Thing, How the West Was Won and all the other fun projects I was lucky enough to have been allowed to be a part of. I had the privilege of working with so many great actors over the years.

According to his website, Arness is survived by his wife, Janet, two songs and six grandchildren.