Budding historian Bill Gray enlisted the help of friends and neighbours in Sacriston when he decided to find out about the card, which had been in his care for some 20 years.
The group began researching the lives of other people in their community during the war and eventually put on an exhibition showcasing their findings.
Now their efforts are to be preserved online after they donated the contents of the exhibition to the Durham at War website (www.durhamatwar.org.uk).
The interactive site, run by Durham County Record Office, was launched a year ago this month to map the story of County Durham and its people during the First World War.
Bill said: “I’m really pleased that the record office has agreed to take on our collection and add it to Durham at War. It’s good to know that what we have done is going to be there for time immemorial.
“I would hate the thought that it was going to sit in a cupboard for years and not be seen by anyone so it’s great that it’s going to be there for future generations.”
The group included local residents Ralph Harrison, Janet Bradley and Gary Meek and other residents. They were supported in their work by Malcolm Smith of Chester-le-Street Heritage Group.
Their investigations revealed that the card that sparked their research project contained the burial details of Bugler Albert Victor Lamb, who was killed by a mortar shell on 27 June, 1916. He was buried at Ridge Wood Military Cemetery in Belgium.
The card would have been sent to Bglr Lamb’s family by the Commonwealth War Graves Commission.
The group also discovered that Bglr Lamb is buried just a very short distance away from his 8DLI comrade William Pickering who he had lived near in Sacriston. The pair died just 13 days apart.
The collection, which was on display in Sacriston Workingmen’s Club, includes a wide variety newspaper cuttings, photographs and other documents chronicling life in the village during the war.
It also includes a street map featuring the names of the village’s fallen and showing where they lived.
There is also information about a medallion, which was commissioned by residents to commemorate the bravery of those who served. Six hundred medallions were produced and presented to Sacriston residents who went to war.
Gill Parkes, principal archivist at Durham County Record Office, said: “The exhibition represents a fantastic effort by members of a fairly small community.
“The material the volunteers have collected clearly demonstrates that there was a very strong sense of community in Sacriston during the war years.
“This commitment to looking after one another is representative of so many villages in the county at the time.”
The material produced by the group will be uploaded to the Durham at War website over the coming weeks. For more information, visit www.durhamatwar.org.uk/story/11516/.
Durham County Council was awarded £475,100 by the Heritage Lottery Fund in 2014 to set up the Durham at War website, which is a partnership venture by Durham County Record office, the council’s archaeology service and the DLI Museum and Durham Art Gallery.