On Friday, Taylor Swift, formerly reticent about entering the political fray, released a new song, “You Need to Calm Down,” that is probably her most explicitly political work. This comes on the heels of her recent advocacy for the Equality Act.

Swift’s activism, which joins that by artists ranging from Beyoncé to Bruce Springsteen on the left, and the likes of John Rich and Kid Rock on the right, seemingly reinforces the perception that in our toxic political environment, everything is political and nothing can truly unify Americans.

But we should not discount the power of music to bring Americans together. One-hundred-fifty years ago this week, the National Peace Jubilee sought to achieve precisely this goal in the wake of a moment far more divisive than today — the Civil War — and its success, though in some ways limited, is a sign that music and grand spectacle could help bridge our bitter divides again today.

The National Peace Jubilee was a musical festival that took place over five days in Boston in 1869. The colossal event represented something that seemed ripped from the pages of P.T. Barnum, the impresario who whipped hordes of Americans into a frenzy with his offerings of larger-than-life talent, promoted with gushing superlatives. In fact, the jubilee was the brainchild of the greatest showman’s onetime employee, Patrick S. Gilmore, who worked for Barnum during the 1850-1852 concert tour of soprano Jenny Lind. In 1864, Gilmore directed the music for the inauguration of Gov. Michael Hahn of Louisiana, displaying his flair for grandiosity with a 500-member band, a chorus of 6,000, 50 cannons and 40 soldiers hammering anvils.

That concert presaged his idea for the National Peace Jubilee. The festival, designed to heal the wounds of the Civil War, was driven by the belief that a spectacular musical performance could be the key ingredient in the nation’s recovery. Given the staggering loss of life in the war, Gilmore reasoned that no gesture of gratitude would be too big to honor the restored national peace. Nor should any expense be spared for a jubilee intended to unite people through the harmony of sound.

The jubilee featured a custom-built structure intended to hold 50,000 people on four acres of land, the largest building of its kind in Boston. The Coliseum, as it was known, was partly situated on what today is called Copley Square. The sprawling edifice would hold an orchestra of 1,000 players and a choir of 10,000 drawn from 103 choral societies mainly from the Northeast. At the time, the star-studded event was the largest musical spectacle ever known.

Gilmore chiefly conducted the music, but he also yielded his podium to local directors, such as Carl Zerrahn and Loring B. Barnes of the Handel and Haydn Society, still a Boston musical stalwart. The musical talent came from around the world, including Norwegian violinist Ole Bull and British soprano Euphrosyne Parepa-Rosa. Of course, there were cannons and anvils too, the former discharged by Boston artillery, the latter struck by 100 local firefighters wearing red shirts, black pants and white caps.

Gilmore intended the festival programming to be broad. The bandleader strove to balance patriotic and popular music with symphonic movements and pieces from oratorios to involve the massive chorus.

The spirit of the event was embodied by the Lutheran chorale that opened it, “God Is a Castle and Defence,” (better known today as “A Mighty Fortress Is Our God”). The “Star-Spangled Banner” resounded throughout the National Peace Jubilee. Though not the national anthem until 1931, the song was met with uproarious applause, and audiences demanded that it be played and encored each day.

Without question, the smash hit of the five-day festival was the still-famous “Anvil Chorus” from Giuseppe Verdi’s 1853 opera “Il Trovatore.” The local firefighters did not disappoint, pounding their anvils “with military precision” for the first three days of the jubilee until they had to return to work.

The second day of the National Peace Jubilee was the high point of the week, as President Ulysses S. Grant paid a special visit. Grant’s arrival in Boston was greeted by full military pageantry. More than 5,000 troops escorted the president to the Coliseum, and the roads were lined with people waving white handkerchiefs. Grant’s appearance was planned well in advance, allowing Gilmore to schedule an appropriate chorus, Handel’s “See the Conquering Hero Comes” from the 1746 oratorio “Judas Maccabeus.”

The National Peace Jubilee generated patriotic fervor through the arts and a display of sheer grandeur. In a city with only 250,000 residents, that week Boston saw some 400,000 people pour in by rail, the most transportation companies had ever witnessed. In a sign that the event was achieving its goal of binding America’s wounds, boats from the southern states brought throngs to Boston Harbor. Concertgoers paid upward of $50 per ticket — about $1,000 today — to see these unprecedented shows. Reporters from 350 periodicals were there chronicling the action across the festival’s five days.

Gilmore envisioned his National Peace Jubilee as “crowning triumph of art and acoustics.” By all reports, it was. But its foremost goal was peace and unity for a broken nation. Though the Civil War had officially ended, Gilmore was concerned about the fragile state of the country.

He wrote: “The primary object of the undertaking was to celebrate the restoration of peace throughout the land. But the questions which now arose were: is there peace throughout the land? What is the condition of the country? . . . How look the clouds that hang over the political horizon?”

Gilmore’s apparent doubts highlight the limits to national unity that could be achieved by the event he orchestrated. In the conductor’s 774-page account of the jubilee, there is no indication that the festival served anyone but white Americans of the North and South.

At the jubilee’s 150th anniversary, unity likewise seems an impossible goal. The United States struggles with questions that underscore national divisions — whether on public policy, gender issues or race relations. Could a grand musical event repair any of those rifts?

In some ways, music has become as political a force as politics itself, with even those once-cautious artists like Swift now embracing political causes and campaigning for candidates. But we should not soon forget that music can be wielded for peace and positive social change. The National Peace Jubilee reminds us that Americans can come out of their corners for entertainment, music especially.

The United Support of Artists for Africa who recorded “We Are the World” in 1985 embodied this spirit. Megaconcerts for disaster relief continue in our time, and sustained and promising initiatives for peace and cultural transformation through music, such as El Sistema, have also changed our world for the better in the last two decades. Social media, instant communication and virtual reality present exciting possibilities for connecting us through passionate performance. In a global landscape splintered in so many ways, music remains a path to recovering our shared humanity and shedding our national divides.