Washington: An 1862 letter to President Abraham Lincoln from three military surgeons requesting a chaplain to tend to the wounded and dying soldiers after the Battle of Antietam, accompanied by the President's signed response, were returned to the National Archives.

Bill Panagopulos, president of Alexander Historical Auctions, in Stamford, Connecticut, helped negotiate the return and handed the documents over to David Ferriero, archivist of the United States, at a ceremony at the National Archives.

"I'm not just returning it to the Archives, I'm returning it to the United States," Panagopulos said. "This building is where it belongs. It's coming home."

Investigators watch carefully for records that should be held at the Archives, Ferriero said. "But we also benefit from dealers who recognize what they have," he added.

Officials believe the documents came from the file of Rev Henry Edwards, who served as chaplain at a military hospital in Hagerstown, Maryland. Citations in red on the letters list a file number that matches the file held at the National Archives building in Washington. But authorities say it's not clear exactly how or when the documents were removed and the circumstances involved.

The surgeons' November 6, 1862, letter asks Lincoln to appoint a chaplain for hospitals treating the wounded from the battle and the cover sheet of Edwards' military file includes Lincoln's November 12, 1862, signed endorsement of the appointment.

Investigative archivist Mitchell Yockelson spotted the letters in a New York dealer's catalog of rare items in 2009. The documents may have been taken while still in the custody of the War Department before they ever became part of the Archives' collection of billions of documents, officials said.