The Mercy Brown exhumations
On 17 March 1892, relatives and neighbours of the Brown family dug up family graves in a church graveyard, looking for a vampire they believed was harming the living.
The Brown family of George Brown, a farmer, lost three members: his wife Mary and his daughters Mary and Mercy. His son Edwin fell gravely ill with the same symptoms, which Atlas Obscura identifies as those of tuberculosis, and neighbours wondered whether a dead relative was preying on the living. History.com says George first doubted the idea and agreed only reluctantly.
On 17 March 1892, relatives and neighbours went to the Brown plot in Chestnut Hill Cemetery, a small graveyard at the back of the Baptist church. Wikipedia adds that a newspaper reporter and Dr. Harold Metcalf, a doctor from the area, were also present. They opened the graves of Mary Brown, and of Mary Olive Brown, and found only bones.
They then dug up Mercy. Wikipedia says Dr. Metcalf reported her body showed a normal level of decay, and that blood found in her heart and liver was an amount he expected from a body buried for that length of time. Yankee Magazine says the men stepped back when they reached her corpse.
"Villagers, the local doctor (Dr. Harold Metcalf), and a newspaper reporter exhumed the bodies on March 17, 1892.[1] The bodies of both Mary Eliza and Mary Olive exhibited the expected level of decomposition, so they were thought not to have been the cause. During examination, Dr. Metcalf reported that Mercy Brown's body was also at a normal level of decomposition, and although blood had dripped out of her heart and liver, the amount was to be expected from a corpse buried for the same length of time.[2]"
- The Last American Vampire, History.com (A+E Networks)
- Grave of Mercy Brown, Atlas Obscura
- Vampire Mercy Brown, Yankee Magazine