At any given time, only about 5 percent of the First Division Museum's 15,000-plus items are on exhibit.
So hundreds of patrons jumped at the chance to get a rare glimpse into the Cantigny Park facility's inner-workings during an open house Saturday, which also featured hundreds more artifacts related to the revered U.S. Army infantry division known as the "Big Red One."
"There's no way to possibly show all that we have here due to space constraints, so this is a wonderful opportunity for our guests," First Division Museum Executive Director Paul Herbert said.
Visitors to the Wheaton museum were able to take a behind-the-scenes tour of the Collections department and see items normally kept under lock and key, including rare helmets, books, uniforms, flags, medals and firearms.
John Maniatis, the museum registrar, pointed out the vault and dozens of tables, shelves and cabinets filled with artifacts such as a Vietnam War-era chaplain kit.
Maniatis explained that when a new item comes in, he measures, weighs, photographs and catalogs it for the curators to research its significance. A collections committee then meets quarterly to vote on whether the museum should keep it.
One of Maniatis' favorite items is a World War I patch that belonged to astronaut Michael Collins' father, who served in the 1st Division. Collins took the patch with him on the Apollo 11 mission to the moon, making the item the museum's most-traveled artifact.
Stephen Johnson, a U.S. Air Force veteran who belongs to the American Legion Cantigny Post 556, enjoyed perusing the newspapers published for infantry soldiers in Vietnam.
"They certainly bring back a lot of memories," said Johnson, who was based in Germany from 1969-73.
Other items on exhibit during the open house included a World War II Scout Car from the museum's motor pool and the "death mask" of Joseph Medill, the grandfather of Col. Robert McCormick. The museum is part of the Chicago-based Robert R. McCormick Foundation.
In the museum lobby, living history re-enactors hosted display tables and let children put on traditional garments while remote-control tanks roamed around.
"I'm a history buff, especially military history, so this is all fascinating to me," said Carl Paperiello of Naperville.