Lincoln Documents Allegedly Exposed to 80-Degree Heat Inside Flawed National Mall Exhibit

Rare copies of the Emancipation Proclamation and the 13th Amendment, both bearing Abraham Lincoln's original signature, have allegedly been exposed to unsafe heat and faulty security inside a brand-new $69 million exhibit beneath the Lincoln Memorial, according to three National Park Service employees and internal communications reviewed by City Cast DC.

The employees, who spoke anonymously as they were not authorised to speak publicly, told the outlet that light-blocking screens meant to protect the documents have malfunctioned, and that temperatures inside the display case have allegedly climbed above 80°F (26.7°C) on multiple occasions.

NPS Denies Any Risk to the Documents

A National Park Service spokesperson disputed suggestions that the artefacts were in danger, telling City Cast DC that staff actively monitor environmental conditions and 'continually manage the space to ensure the documents are cared for'. The spokesperson did not answer questions about the case's temperature on any specific date, including its reported peak, or confirm a target temperature range.

The agency also declined to explain why a fan was seen pointing at the display case during a visit by City Cast DC last week, and did not respond to claims that the exhibit's 'sally port' entrance system, a security measure using two sets of doors that should never open simultaneously, was faulty.

Preservation Standards Say Otherwise

Katie Lowe, a preservation specialist at the Conservation Center for Art and Historic Artifacts, told City Cast DC that historic documents should never be kept above 75°F (23.9°C), and even then only with humidity and light tightly controlled. Heat, she said, accelerates decay through mould, embrittlement, yellowing and ink corrosion.

By comparison, the National Archives keeps its own Charters of Freedom, including the Constitution and the Declaration of Independence, at roughly 67°F (19.4°C) inside sealed, monitored cases, according to a 1999 National Archives fact sheet on the documents' encasement standards. The National Archives' public guidance also recommends storing family archives below 75°F (23.9°C).

Lowe said she was unsure why the Undercroft was displaying originals rather than facsimiles, copies often indistinguishable to the naked eye that museums commonly use to protect fragile items. 'A year is certainly enough time for damage to occur,' she said, referring to the length of the current loan.

A Billionaire's Loan and a String of Other Problems

The documents are on loan through June 2027 from hedge fund billionaire Kenneth C Griffin, who bought them at auction last year for a reported $18 million. Griffin did not respond to requests for comment. The Undercroft's broader restoration was separately funded in part by an $18.5 million gift from philanthropist David Rubenstein.

Beyond the heat claims, two NPS officials said the sally port system has already failed once, when a child allegedly pushed open the first set of doors while the second remained ajar, an incident City Cast DC says it confirmed last week. The Undercroft has also suffered a power outage that shut the museum for a day and a shattered glass door in an elevator bay, though no one was hurt in either case.

The Interior Department opened the 15,000-square-foot Undercroft on 25 June, part of a nearly decade-long, $69 million project first awarded in 2023. The exhibit is one of several America250 attractions tied to the country's semiquincentennial.

The Emancipation Proclamation copy on display is one of just 27 known survivors of 48 signed by Lincoln in 1864 to raise money for wounded Union soldiers, while the 13th Amendment copy is one of only 15 like it. If the alleged conditions are accurate, campaigners for historical preservation say it raises questions about how a flagship national monument, opened during America's 250th anniversary celebrations, is safeguarding some of the country's rarest constitutional artefacts on loan from a private donor.