[8] Antietam National Cemetery, which adjoins the park, covers 11.36 acres (4.60 ha) and contains more than 4,976 interments (1,836 unidentified).

[9] The cemetery was commissioned in 1865, and interments began in 1867, following an arduous process of identifying the remains, which was only successful in about 40% of the cases.

[9] However, two exceptions have been made; the first in 1978 for Congressman Goodloe Byron and the second in 2000 for the remains of USN Fireman Patrick Howard Roy who was killed in the attack on the USS Cole.

[9] The cemetery was placed under the War Department on July 14, 1870;[11] it was transferred to the National Park Service on August 10, 1933.

[12] The gatehouse at the cemetery entrance was the first building designed by Paul J. Pelz, later architect of the Library of Congress.

The Antietam National Battlefield Visitor Center contains museum exhibits about the battle and the Civil War.

The luminaries consist of a paper bag filled with sand and a candle, and represents a soldier that was killed, injured, or went missing during the Battle of Antietam.

[19] The preservation organization has since removed the postwar house and barn that stood on the property along Hagerstown Pike and returned the land to its wartime appearance.

[21] As the fighting in the cornfield was coming to a close, Maj. Gen. William H. French was moving his Federals forward to support Maj. Gen. John Sedgwick and veered into Confederate Maj. Gen. D.H. Hill's troops posted in the Sunken Road.

[21] On the southeast side of town, Union Maj. Gen. Ambrose E. Burnside's IX Corps had been trying to cross Antietam Creek since mid-morning, being held up by only 500 Georgia sharpshooters.