Spectators can watch the re-enactments as well as shop for period relics and talk to re-enactors about what it was like to live during that era.
Events include a 19th-century baseball game between the 12th New Jersey and the 18th North Carolina Saturday morning.
A.P. Hill's attack will be re-enacted at 3 p.m. Saturday.
"That represents the climax of the battle. It was the last attack of the day. It saved General Lee's army from destruction," said Dennis E. Frye, co-chairman of the Antietam Commemoration Committee.
Two re-enactors will get married in an authentic Civil War-era wedding at 5:30 p.m. Saturday.
The Cornfield Battle will be re-enacted Sunday morning at the actual time it occurred - 6:30 a.m.
The sound of troops marching to battle at dawn is "one of the most eerie sounds. You can't see but you can hear thousands of feet tramping quietly. You know something is moving out there, but you can't see it," Frye said.
There will be a 19th-century style temperance rally at 11 a.m. Sunday.
The Sunken Road or "Bloody Lane" battle will be re-enacted at 1:30 p.m. Sunday.
The Civil War-related activities don't end at the re-enactment site. People interested in Civil War history can become immersed this weekend at any number of events happening in the county.
Sharpsburg Heritage Festival will feature living history, Civil War merchants known as sutlers and booksignings. Free shuttle buses will run between the re-enactment site and Sharpsburg.
Antietam National Battlefield is stepping up its schedule of interpretive programs and lectures.
In downtown Hagerstown, people can go on a ghost tour walk Friday and Saturday evenings, sample a camp meal, listen to lectures or attend a booksigning.
The Maryland Theatre will show the movie "Gettysburg," Friday and Saturday nights.
A Maryland Symphony Orchestra concert at Municipal Stadium Saturday night will feature selections of America's favorite folk music, including songs popular during the Civil War. Fireworks will follow the concert.
Valley Mall will have a living history program Saturday afternoon.