The monument to Major General Abner Doubleday is west of Gettysburg on Reynolds Avenue. (39.83303° N, 77.25075° N; map)
The nine foot tall bronze statue was created by John Massey Rhind and stands on an eleven foot tall granite base. It was dedicated on September 25, 1917 by the State of New York.
From the tablet on the front of the monument:
Cadet U.S.M.A. Sept. 1, 1838. Brevet Second
Brigadier-General U.S.V. Feb. 3, 1862. Major-
Commanding Second Brigade, First
Brevetted Lieut.-Colonel U.S.A. Sept. 17,
Brevetted Brigadier-General and
Abner Doubleday was born at Ballston Spa, New York, on June 26, 1819, the son of a congressman. He graduated from West Point in 1842, serving in the artillery.
Doubleday was literally at the start of the Civil War in the garrison at Fort Sumter, firing the first gun in reply to the rebel bombardment. Commanding a brigade and then a division in the Army of the Potomac, he found himself in charge of the 1st Corps at Gettysburg with the death of John Reynolds.
The 1st Corps fought well all morning, outnumbered but inflicting grave casualties on its opponents. But along with the 11th Corps north of town, it was eventually overwhelmed and forced into a chaotic retreat through town to Cemetery Hill.
On July 2nd, Meade put General John Newton in command of the 1st Corps, relegating Doubleday back to division command. Although Newton was a classmate, he was junior in rank to Doubleday by six months, but Meade had little confidence in Doubleday's abilities. To add injury to insult, Doubleday was wounded in the neck on July 2nd.
After the battle Doubleday formally requested reinstatement as 1st Corps commander, but Meade refused, and on July 7th he left the army for Washington. He spent most of the rest of the war on administrative duties, and had a chance to get back at Meade by testifying against him in the congressional hearings over Gettysburg.
After the war he reverted to Lieutenant Colonel, commanding troops in Texas and San Francisco and becoming the President of the American Theosophical Society. He died in 1893 in Mendenham, New Jersey.
Doubleday's connection with baseball comes from a 1907 report that credited him with devising the game in 1839, when he would have been a cadet at West Point. However, there is no evidence to support this, none of Doubleday's many papers mention the game or any connection to it, and the author of the report was committed to a mental institution, so there is reason to doubt the validity of the claim.