WARREN, Maine (AP) _ A graphic, unsparing first-person account of the Civil War could fetch up to $120,000 this Saturday, according to its auctioneer.

The 300-page manuscript by Gen. Ellis Spear is attracting attention from collectors nationwide, said Kaja Veilleux of Thomaston Place Auction Galleries.

Spear was an officer in the 20th Maine Regiment who fought alongside Civil War hero Joshua L. Chamberlain at the battle of Gettysburg.

Spear's original handwritten manuscript was recently discovered in the attic of his one-time homestead in Warren.

Though the manuscript dates to around 1905, it was based on a diary Spear kept during the Civil War, said Dave Fletcher, who has been cataloging and researching items for the auction.

The manuscript provides a “brutal, open-eyed,” description of the Civil War, Fletcher said.

Spear, who graduated from Bowdoin College in 1858, was positioned at Little Round Top during the battle of Gettysburg.

His manuscript provides a vivid description of the battlefield _ dead soldiers face-down in the dirt, and a barn that caught fire with several charred bodies of Confederate soldiers trapped inside.

“The fact that he wrote this gritty account without glorifying the war, to me, is pretty amazing,” Fletcher said.

In 1997, Spear's grandson wrote a book that was based on his diaries and the manuscript.

On Friday afternoon, an auction preview will provide collectors the opportunity to walk through Spear's home. About 500 people are expected to attend the auction, which will begin Saturday at 11 a.m.

Also up for auction will be Spear's 1863 map of the Gettysburg battlefield and an admission ticket to the 1868 U.S. Senate impeachment proceedings of President Andrew Johnson.