Johnny O's owner Johnny Veliotis has died. View Full Caption DNAinfo/ Mark Konkol

CHICAGO — Johnny Veliotis, founder of iconic Bridgeport hot dog spot Johnny O's, died Thursday afternoon.

Johnny Veliotis was a "character" in the neighborhood, said his son, Peter Veliotis. He'd started out as a poor Greek kid selling hot dogs out of a cart by Old Comiskey and ended up opening Johnny O's, singing the National Anthem at the park and being featured on TV.

"He had a big heart and he helped out a lot of people," said Peter Veliotis. "He looked out after a lot of people. He was kind of a father figure to many, many people in the neighborhood here."

Johnny O's, 3465 S. Morgan St., has been a South Side mainstay since it opened in the late '70s. It's known for its hot dogs and Italian beef, Peter said, but Johnny Veliotis' fame went further beyond the restaurant: He was known for sponsoring many sports teams in the neighborhood, and he had put out music as a young crooner. He was even asked to sing the National Anthem at Comiskey in 1980.

Johnny O's founder Johnny Veliotis sings the National Anthem at Comiskey in 1980. View Full Caption Courtesy Peter Veliotis

And Johnny Veliotis would still sing to the guys who came by Johnny O's every once in a while, Peter Veliotis said.

"Dad was quite a character and had a lot of personality and charm," Peter Veliotis said.

Johnny Veliotis got his start selling hot dogs out of a cart when he was just 12 years old. He expanded to two carts and opened his first restaurant, called Johnny O's Famous Beef Stand, at 812 W. 31st St. He owned several other restaurants throughout the years.

Johnny O's became famous for its "Mother-in-Law," a tamale served on a hot dog bun with chili, onions, tomatoes and sport peppers. The sandwich has earned Veliotis' restaurant spots on television programs like TLC's "Best Food Ever" and WGN's "Chicago's Best" for years.

“I don’t even know how the Mother-in-Law got its name but I used to sell it off a push cart when I was a kid, 11 or 12 years old,” Johnny Veliotis told DNAinfo in 2015. “We used to put a hot tamale on a bun and what made ours special was that we threw the kitchen sink on it. So years ago, for 5 cents you got a meal.”

Plans for memorial events have not yet been finalized, Peter said, but information will be shared on Facebook.