WATCH: Cows come home to Chicago!
"Harry Caray was known for saying 'Holy Cow!' so it was the biggest no-brainer in history," said Grant DePorter, of the cow sculpture on display inside Harry Caray's restaurant.
It might seem like a no-brainer now, but when the city first began the public art exhibition in June 1999, they had no idea how it would take off in popularity. Nathan Mason was the curator - and it was his first job with the city.
"I had no idea it would be so successful. I thought it would be a fun project but then it just went overboard," Mason said.
The original goal of 100 cows eventually turned into 340 all over the city. Eventually they were auctioned off, raising $3.5 million for charity. But that's nothing compared to the estimated 2 million tourists the exhibit drew to the city and the more than $200 million of economic impact.
Some of the favorites from 1999 are now back in Chicago for the 20th anniversary. Through the end of the month, they will be on display at Jane Byrne Park next to the Water Tower on Michigan Avenue.
Some of their fellow cows are on permanent display at places like Harry Caray's, which claims the largest herd of five cows.
The 'Holy Cow' at Harry Caray's original restaurant on Kinzie might be the most famous. It's been photographed an estimated 600,000 times, many with people sitting on it.