An extraordinary piece of American history, the flag that draped the casket of former President Abraham Lincoln during his funeral procession, has found an unexpected new home—in a Midtown Manhattan steakhouse.

Keens Steakhouse, a venerable 141-year-old establishment renowned for its impressive array of Americana memorabilia, revealed this half-million-dollar auction acquisition during a private event on Thursday.

“It’s truly a treasure,” Julia Lisowski, the general manager of Keens Steakhouse, remarked to The Post about the historic flag, which played a part in Lincoln’s funeral procession following his assassination in 1865.

“Having such a significant piece of history here is both special and amazing,” she added.

The 37-star American flag, believed to be the sole surviving casket flag from Lincoln’s funeral journey from Washington, D.C., to his final resting place in Springfield, Illinois, will be on permanent display in the restaurant’s second-floor “Lincoln Room.” This space, filled with presidential artifacts, offers diners a taste of history alongside classic dishes like mutton chops and Porterhouse steaks.

According to Lisowski, the flag’s relocation to New York is somewhat of a homecoming. It was originally crafted by Annin & Company, a historic flag-making firm located on Fulton Street, known as the nation’s largest and oldest establishment of its kind.

As part of the funeral train procession, it traveled on a 1,600-mile journey through hundreds of US towns in 1865– and even passed through City Hall in Manhattan.

Known as the Applegate Flag due to its provenance handed down through generations of the descendants of army doctor Lewis Applegate’s family for more than 150 years, the flag was first gifted to the physician from Sen. Edwin D. Morgan — who was one of only six Senate pallbearers who rode with the funeral train, Lisowski said.

After exiting the Applegate lineage in 1977 and exchanging hands in two other families, the flag was donated to the Museum of Southern History in Jacksonville, Florida in 1996 — until it was rediscovered “down a dark hallway behind a bookcase” during an inventory check in 2023.

It was around that time that Keens ownership also changed hands to billionaire Tilman Fertitta for a cool $30 million.

Lisowski called it “kismet” that Fertitta stepped into the role as auction house Guernsey’s put the flag up for sale in 2024. The hospitality mogul, behind the likes of the Rainforest Cafe and Bubba Gump Shrimp, grabbed the famed flag for $525,000.

But it still took months to bring the American history relic back to life, Lisowski said, as the flag then went through a monthslong restoration process at the St. John the Divine’s Textile Conservation Laboratory.

Lab director Marlene Eidelheit recalled the flag was thoroughly examined and treated for a few tears and dirt — but it “wasn’t bad” as far as presidential Civil War-era artifacts go.

The flag joins a swath of Lincoln memorabilia in Keens’ upstairs dining room, including political cartoons; a famous Bixby letter from Lincoln to a Union army widow who lost her five sons in the Civil War; and a stained program that a nearby framed article claims Lincoln was holding at Ford’s Theatre when he was fatally shot by John Wilkes Booth.

The flag also serves as the first 21st-century addition to Keens’ extensive “Lincoln Room” collection, and the latest acquisition since at least the 1950s.

“Guests come to Keens not just for a meal, but for a sense of history; and The Abraham Lincoln Casket Flag 1865 is one of the most meaningful artifacts we have ever had the privilege to display,” Lisowski added.

“Keens has always been a steward of American history, and welcoming this extraordinary piece into our Lincoln Room allows us to honor President Lincoln’s legacy in a way that feels both intimate and profound.”