Built in 1806 at a cost of $7,700, the meetinghouse sits on a quiet side street in Boston's upscale Beacon Hill neighborhood, in the shadow of the Massachusetts Statehouse and nestled among handsome brownstones and exclusive private residences.
Long before modern office towers would hold sway, the building could be seen from the city's bustling waterfront, a "beacon on a hill" for black people longing for freedom, Morgan-Welch said.
It was one among a series of firsts for Boston's vibrant black community, which by that time had already formed the young nation's first black Masonic order, an African Benevolent Society, and the African School. Though designed as a place for worship, education, social gatherings, and cultural events - The Marriage of Figaro was once performed there - it secured a place in history by becoming a headquarters of sorts for the antislavery movement.
"They prayed, they sang, they had songs like 'I'm an abolitionist' put to the words of 'Auld Lang Syne,' " said Morgan-Welch, who described congregants as coming from every walk of life, including business owners, craftsmen, servants, and seafarers.
Garrison formed the New England Anti-Slavery Society in the basement of the building in 1832.
"We have met to-night in this obscure school-house; our numbers are few and our influence limited; but, mark my prediction, Faneuil Hall shall ere long echo with the principles we have set forth. We shall shake the nation by their mighty power," Garrison said, according to the historical record. The words are among those inscribed on a granite plaque outside the building.
Faneuil Hall, a short stroll from the meetinghouse, played a key role in the buildup to the Revolutionary War.
Douglass, who escaped from slavery to become a leading abolitionist, made one of several visits to Boston on Dec. 3, 1860. Historical records reveal a gathering at which he encouraged participants to present ideas for "the best way of prosecuting the anti-slavery movement," listing both war and peace as possible avenues.
As war approached, the sense of urgency within the meetinghouse heightened.
Rallies were held to urge blacks to sign up for the 54th and 55th black regiments that would fight in the Civil War.
"They are preparing for war, they are preparing for what they know will come, they are extremely well organized," Morgan-Welch said.
The story of the 54th Regiment was chronicled in the film Glory.
The African Meeting House building faded in prominence after the Civil War and was sold in the late 19th century. For the next seven decades of its existence it would be a Jewish synagogue, before being purchased by the museum in 1972.
Though named a national historic landmark in 1974, it wasn't until 2006 that full-scale restoration began. The goal was to restore the meetinghouse's mid-19th-century character as much as possible. No detail was overlooked, down to the square-headed nails typical of the time and replicating the original paint.
"They had people come in and do microscopic analysis of all the paint layers," said Carl Jay, director of historic preservation for lead contractor Shawmut Design and Construction.
In addition to the restoration of the original structure, a new wing was constructed for elevators and other modern amenities.
The sanctuary's curved pews are re-creations of the originals, based on sketches from the time but enlarged to accommodate average modern-day heights and weights.
Morgan-Welch recalls bursting into tears the first time she looked into the completely restored sanctuary.
"Frederick Douglass walked here," she says, slowly and almost reverently. Seated in the balcony, reachable by the same spiral staircase that congregants would have climbed two centuries ago, she reflects on what she hopes visitors will take away from the building.
"I would like them to understand that black people in America by 1806 had built for themselves a mighty, elegant, and embracing space in which to worship, to educate, and to end slavery," she said.
African Meeting House:
46 Joy St., Beacon Hill, Boston. Hours: Mon-Sat 10 a.m.-4 p.m. Admission: Adults, $5; children 12 and under, free; seniors 62 and over and teens 13-17, $3. 617-725-0022; www.maah.org/ afmbeaconhill.htm.