Joan Jett revealed that her favorite piece of memorabilia wasn’t a rock ’n’ roll keepsake, but a presidential declaration written by Abraham Lincoln.

The letter is dated March 1863, midway through the 16th U.S. president’s term of office, which began two years earlier and ended with his assassination in April 1865. It was given to Jett by her late friend Paul O’Neill, the creator of prog-metal band Trans-Siberian Orchestra, who died in 2017, months after giving her the gift.

“I have a declaration from Abraham Lincoln hanging in my hallway,” Jett told The New York Times in a new interview. “It authorizes one guy, William T. Otto, to perform the duties of the office of the Secretary of the Interior. Abraham Lincoln wrote it, and he had very neat handwriting.”

Jett noted that "it's a museum piece, an actual piece of history. My family lived in Maryland from the time I was 8 to when I was 13 years old, so I spent a lot of time going to museums in D.C. I got to see a lot of early American history, a lot of Lincoln history.”

She went on to described O’Neill as “like my brother."  “He was the lead singer of the Trans-Siberian Orchestra, but we first met when he started out as a tour manager at the beginning of the Blackhearts," she said. "He helped do whatever we needed to do when we were on the road and struggling. Once we weren’t struggling anymore, he left to make his own music. My partner, Kenny Laguna, and I sort of gave him seed money to start his own music projects and what became TSO. We were very connected.”

Jett recalled how O’Neill would often buy her “crazy, over-the-top gifts like this or like a $10,000 guitar." “He was always trying to show that he recognized that Kenny and I had something to do with him having success, and he just wanted to give back,” she explained, adding that the declaration added “extra weight” because he’d given it to her the last time they’d been together, at New Year’s Eve 2016.