Carol Appenzellar, project manager for the library's Historic Newspaper Indexing Project & Special Historical Projects, spent 18 months sorting the documents.
Volunteer Buck Macht, who reviewed some of the documents, said he was struck by how interested in and supportive Hartle was of his troops.
Appenzellar said she learned the general referred to his wife in letters as "my mommy," saw a photo of Hartle and Queen Elizabeth in a Jeep, and learned that Eisenhower reprimanded Hartle. She also mentioned a mystery surrounding Hartle's transfer from the ETO to a Texas training camp.
Joe Lallande, Hartle's great-nephew who lives in Maine, recalled that Hartle and his wife were gracious to him and his sisters when they were children.
"I can remember him taking me fishing somewhere in the area of Hagerstown," Lallande said. "He had a very deep voice and he just had a presence about him."
Lallande said he wasn't positive why Hartle was nicknamed Scrappy.
"I believe it had to do with bulldog tenacity or perhaps maybe even a little bit of a temper," Lallande said.
While Hartle is not a household name like field generals Eisenhower and MacArthur, he had an impact on history.
In 1942, when the authorization came to establish the first U.S. Army Ranger Battalion, it was Hartle who appointed his aide-de-camp, Capt. William O. Darby, to organize such a unit, according to www.ranger.org.
In an Aug. 25, 1942, letter to "Scrappy," Eisenhower commended Hartle for developing methods for "establishing harmonious relations" between black and white troops while stationed in Northern Ireland.
"I have passed on the document to other commanders in the belief that your scheme may have a general application, to the benefit of the whole command," Eisenhower said.
But Ike also took Hartle to task.
In a Sept. 22, 1942, letter, Eisenhower admonished Hartle for statements he made to the media regarding methods to win the war.
In an article in the Evening Standard, Hartle said, "It might be a good idea to lose thousands of thousands, to martyr a percentage of our forces in order to chop a couple of years off the war."
Eisenhower's responded in a letter to Hartle, saying "I realize that there is probably a mistake tied up in the matter somewhere, but as this type of thing always gets me in hot water I am sending you this note. Please avoid giving out quotes on such subjects."
Then, there is the matter of Hartle's mysterious transfer.
Hartle was preparing to take his command from London to Northern Africa to help with the war effort when he was ordered stateside and stationed at Camp Fannin in Texas, Appenzellar said.
In Hartle's correspondence at the time, he told friends the transfer was a routine rotation of assignments, Appenzellar said.
But that's unlikely, she said.
Herald-Mail archives include a story that states Hartle was transferred back to the U.S. due to illness and received a physical disability retirement in 1946.
Lallande said old family lore suggested Hartle "failed to exercise the appropriate protocol with the queen. But I have no basis in fact other than that's the story that my father had passed along."
More indicative of the reason for Hartle's transfer might be in the papers of Gen. George C. Marshall.
Inquiries to the U.S. Army Military History Institute in Carlisle, Pa., and to the Dwight D. Eisenhower Library in Abilene, Kan., point to earlier documents that indicate Marshall's dissatisfaction with having Hartle, a two-star general, appointed to command invasion forces for the invasion of North Africa.
According to research from the Eisenhower Library, a Sept. 26, 1942, radio message from Marshall to Eisenhower includes the partial quotes:
"I am now even more disturbed over the selection of Hartle for a vital command," and "to put him (Hartle) in charge of the key operation disturbs me greatly."