The Battle of Antietam was a key battle during the Civil War that took place on September 17, 1862. After the engagement, President Abraham Lincoln issued the preliminary announcement of the emancipation proclamation. The National Park Service website on Antietam has a number of great resources, including historic photographs by Alexander Gardner, Captain James Hope’s paintings, and a gallery of antique postcards. Teachers can find curriculum materials as well – these include lesson plans, a primary sources packet, worksheets, and scavenger hunts. Visitors can also find a nice timeline, and details on the Army of the Potomac and Army of Northern Virginia. Historyanimated.com, a non-profit educational foundation, has a great battle animation of Antietam. Antietam on the Web also provides a number of great resources, including links to all 315 of the commanders’ After-Action Reports published in the Official Records.