In 2004, author A. J. Bastarache decided to find the location of the baseball diamond described in documents and newspapers from 1878.

This baseball diamond was home field to future Hall of Famer Tim Keefe and Billy "Sliding" Hamilton. They were the greatest players in their day and pioneers of the game.

Billy Hamilton's 937 career stolen bases and single-season total of 115 records stood until 1970

Tim O'Keefe is ranked the 7th greatest picture of all-time and still holds major league records - 19 consecutive wins and career strike-outs.

After six months of research, A. J. Bastarache was about to abandon the search. The only information he had was a hunch as to where the original field was (Fuller Field) and a 1878 newspaper article calling it "the grounds."

A. J. asked the historical society again for help. This time, did they have the other half of a map he had purchased from 1870. Perhaps that would show the diamond location. Betty returned from a small room without the 1870 map, but with something better, a map from 1878, the year the pro team started playing at this diamond.

As Betty unrolled the map, an amazing sight appeared. In the exact location suspected were the words "Base Ball Grounds." Better still, the baseball diamond itself was drawn out on the map. Not only was the location of the old baseball diamond discovered, but the baseball diamond is in exactly the same location as the diamond used today, Fuller Field.

A few weeks later, while researching other parts of the book, the author wondered how this baseball diamond ranked in relation to others. It was 34 years older then Boston Fenway Park. He knew that professional baseball began around 1875 so perhaps it was one of the oldest.

After two months of research and confirming that all baseball diamonds that predated 1878 were either destroyed or moved, A. J. concluded that Fuller Field in Clinton, Massachusetts was in fact the Oldest Baseball Diamond in the World in continuous use.

It would take the A. J. two more years of research, documentation and confirmations until Guinness World Records agreed with the claim and on September 11, 2007, sent A. J. Bastarache the two documents above confirming the discovery.