Baseball dated back to 1791

The earliest previous reference to baseball was said to be 1823

Officials and historians in the US state of Massachusetts have released a 213-year-old document they believe is the earliest written reference to baseball.

A 1791 bylaw aimed to protect the windows in the town of Pittsfield's new meeting house - by banning baseball within 80 yards of the building.

The bylaw would have been written before 1839, the long debunked date when baseball was thought to have been invented by Abner Doubleday in Cooperstown, New York.

The document, released on Tuesday, has been verified by the Williamstown Art Conservation Center in Massachusetts.

"This is a wonderful story," the National Baseball Hall of Fame chief curator Ted Spencer said.

"This is a great piece of history in the development of the game."

'Not born anywhere'

A generation ago, the popular belief was that baseball was invented in 1839.

Later evidence suggested it was in 1846, in Hoboken, New Jersey. Subsequently, a New York University librarian found two newspaper references to some form of "base ball" in 1823 in New York City, the New York Times reported.

Historian John Thorn was researching the origins of baseball when he found a reference to the bylaw in an 1869 book on Pittsfield's history.

"It's clear that not only was baseball played here in 1791, but it was rampant... enough to have an ordinance against it," Mr Thorn said.

Pittsfield is baseball's Garden of Eden James Ruberto

The original document was located, verified and displayed at a news conference.

"Pittsfield is baseball's Garden of Eden," the city's Mayor, James Ruberto, said.

But experts say it may be impossible to say exactly where and when baseball was born.

"There's no way of pinpointing where the game was first played," said a spokesman for the Hall of Fame.

"Baseball wasn't really born anywhere."

If the Pittsfield group's document is authentic, it would be "incredibly monumental", he said.