The Gettysburg National Military Park and Gettysburg Foundation are among the sponsors of a $100, three-day seminar on Sept. 12 to 14 titled “The Unfinished Work: Abraham Lincoln, David Wills and the Soldiers’ National Cemetery.”

The seminar will explore the humble beginnings of the cemetery and “its physical evolution, and how this hallowed ground and the Gettysburg Address still inspires Americans 150 years later,” according to the Park Service.

Discussions will include Wills’s plan for a national cemetery and its development, President Abraham Lincoln’s visit to Gettysburg, the meaning of the Gettysburg Address and the experience of the wounded at Gettysburg, according to information about the seminar.

Guided field walks, house tours and an optional horseback tour of the park are also on the schedule.

The venues change often and will include the cemetery, George Spangler Farm, David Wills House, Gettysburg Train Station and the Visitor Center and Museum.

Participants are free to attend all the events or just a few. Registration is by mail.