In 1895, the battlefield was established by act of Congress as Gettysburg National Military Park. In that year, the Gettysburg Battlefield Memorial Association, which had been founded April 30, 1864, for the purpose of commemorating “the great deeds of valor, endurance, and noble self-sacrifice, and to perpetuate the memory of the heroes, and the signal events which render these battlegrounds illustrious,” transferred its holdings of 600 acres of land, 17 miles of avenues, and 320 monuments and markers to the Federal Government. Under the jurisdiction of the War Department until 1933, the park was transferred in that year to the Department of the Interior to be administered by the National Park Service. Today, the park consists of 2,554.82 acres of land and 26 miles of paved roads.

The fields over which the battles were fought cover about 16,000 acres and include the town of Gettysburg. A total of 2,390 monuments, tablets, and markers have been erected over the years to indicate the positions where infantry, artillery, and cavalry units fought. Of the 354 Union and 272 Confederate cannon engaged or held in reserve during the battle, 233 Federal and 182 Confederate are located on the field in the approximate position of the batteries during the battle.