– In 1864, Abraham Lincoln made a rare wartime trip out of Washington to visit a charity event in Philadelphia raising money to care for wounded soldiers. He donated 48 copies of the Emancipation Proclamation to be sold for fundraising.

But it turns out he received a gift in return: a Bible whose pages were edged with gilt and decorated with the words "Faith," "Hope" and "Charity" after 1 Corinthians 13:13 — a holy book at a time when Lincoln was turning increasingly to Scripture to understand personal tragedy and national trauma.

Now, more than 150 years later, historians have become aware of the Bible for the first time, a unique artifact of the 16th president's life that they did not even know existed.

Given by his widow to a friend of Lincoln's after his assassination, it has remained out of sight for a century and a half, passed along from one generation to another, unknown to the vast array of scholars who have studied his life.

On Thursday, it went on display at the Abraham Lincoln Presidential Library and Museum in Springfield, Ill., a bequest from the family of the Rev. Noyes Miner, who lived across the street from the Lincolns in the Illinois capital and spoke at the slain president's funeral.

After preserving the Bible over the decades, Miner's descendants recently came forward to disclose its existence and donate it.

"For me, it's a physical connection with Abraham Lincoln," said Alan Lowe, executive director of the library and museum. "We see it as an important artifact to preserve for history's sake, but also the beginning of a conversation about the relevance of Lincoln and the role of religion in our lives today."

The Bible is the sixth known to historians to have been owned by Lincoln and his family. The most famous, the one on which Lincoln placed his hand at his 1861 inauguration, is held by the Library of Congress and was used by Barack Obama to take the oath of office in 2009 and 2013 and by Donald Trump in 2017.

The newly discovered Bible is more than twice as large, about 14½ inches long by 11⅝ inches wide. Mary Lincoln, who gave it to Miner seven years after her husband's death, had it inscribed: "Mrs. Abraham Lincoln to N.W. Miner, D.D., Oct. 15, 1872."

Miner, a friend of the president's, was "very much beloved by my husband," according to Mary Lincoln. During his years in Springfield, Lincoln regularly stopped by Miner's house to visit.

Historians at the library speculate that the former first lady gave the Bible to Miner, a Baptist minister, as part of her post-White House campaign to protect her husband's legacy. She angrily rejected assertions by his former law partner William Herndon that Lincoln had been an atheist.

Lincoln's faith has been a source of debate among scholars. Growing up, he rejected his parents' Baptist religion, seeing it as too emotional. He never joined a church, and as a young man was viewed as the "village atheist."

But biographers say he evolved as he grew older, influenced by the deaths of his sons Edward at age 4 and later Willie at age 11, as well as by the horrific slaughter of the Civil War. He attended services at the New York Avenue Presbyterian Church in Washington and often quoted the Bible.

The Bible remained in Miner's family through the years. Sandra Wolcott Willingham, Miner's great-great-granddaughter, said her grandparents displayed it on a tall table in the sitting room in their house in Oyster Bay, N.Y.

In 1994, the Bible was left to Willingham's son, William Prescott Wolcott Jr., of San Francisco. Willingham, of Idaho, recalled wrapping the Bible in a beach towel to drive it to her son's house, where it was displayed on a mantel.

During a cross-country trip last year, Willingham and her husband stopped in Springfield and visited Lincoln's home. Shown the lot across the street where her relatives' house once stood, they decided to visit the museum, and told Ian Hunt, head of acquisitions, about the family keepsake.

When the family agreed to donate it, Lowe and Hunt flew to San Francisco to authenticate it.

"They came in with their white gloves on," Willingham recalled. "They were speechless."