The Friends of Hopewell Furnace will host a presentation on Colonial iron workers, who created various products, including the cannons for George Washington's army. Historian and author Daniel A. Graham will present the program on Sunday, May 17, at 2 p.m. at the Hopewell Furnace Visitor Center, 2 Mark Bird Lane, Elverson.

The event is free of charge. Seating is limited. Graham will also be available to sign copies of his books, which may be purchased at the Visitor Center and at http://www.friendsofhopewellfurn.org.