The plaque to honor Philip Reid was unveiled during a ceremony in Hyattsville, Md. “Philip Reed” is the spelling the former slave chose to use after he was freed. (Michael S. Williamson/The Washington Post)

Philip Reid, who suffered many indignities in death as well as in life, has finally gotten the recognition due him 134 years after he was first buried.

A former slave who played a pivotal role in casting the giant bronze Statue of Freedom atop the U.S. Capitol dome, Reid now has a historical marker at the National Harmony Memorial Park in Hyattsville noting his contribution and that he died a free man.

The marker was unveiled fittingly on Wednesday, Emancipation Day, which commemorates the day in 1862 President Abraham Lincoln abolished involuntary servitude in the District. That is how the slave who helped construct the symbol of freedom over the Capitol gained his own freedom.

The marker, arranged and paid for by a writer trying to shed light on significant but overlooked moments in American history, is in a section of the cemetery where a garden will be planted and named for Solomon Northup, who wrote “Twelve Years a Slave.”

The site is about a full football field away from Reid’s remains, which are in an unmarked mass grave filled with unclaimed bodies relocated several decades ago when the Rhode Island Avenue Metro station took over the cemetery where they had been. The new placement helps ensure that more visitors will see the marker and reflect on Reid’s accomplishments, cemetery officials said,

“I’m delighted to be here and make a small attempt to rectify one of the forgotten places in our history,” said the Rev. Wallace Charles Smith, pastor of Shiloh Baptist Church, one of the oldest African American churches in the District. “We hope that succeeding generations will not forget the great legacy of Mr. Philip Reid, who in spite of being a slave with no resources and bearing his master’s name, helped create one of the most iconic statues — the Statue of Freedom.”

The bronze marker honors the accomplishments of “Philip Reed,” with the spelling that Reid used after he was freed. In official documents of the Architect of the Capitol and other historical government papers, he is identified as Philip Reid, the name given him when he was purchased for $1,200 by foundry owner Clark Mills.

He still owned Reid when the government paid Mills $400 a month to lease his Bladensburg foundry for the casting of the statue designed by Thomas Crawford. The federal government paid Reid $1.25 a day for “keeping up fires under the moulds,” according to the architect’s account. But Mills pocketed six days of Reid’s wages, and Reid only kept his pay for one day a week, Sunday — earning a total of $41.25 for 33 Sundays.

Without Reid, the plaster model of the statue might never have made it to the foundry.

The bolted-together model had been set up in the Capitol for tourists to look at. But when it came time to cast it, nobody could find a way to separate it so it could be moved to the foundry. Reid figured out how to use a pulley and tackle to lift up the model and pull it apart for easy transport.

In a change rife with poetic justice, he already was a free man when the job was completed in December 1863.

The cemetery marker at National Harmony is not the first to note Reid’s achievements. He had a marker at the old Harmony Cemetery, too. But the marker vanished when the cemetery was moved before the construction of the Metro station, said Andrew Carroll, the author who has made rediscovering forgotten history his life’s work. Reid’s remains were placed into the mass grave after none of his descendants answered letters notifying them of the impending change, according to Carroll.

Carroll is now single-handedly going around the country reminding people of places where American history was transformed.

Proceeds from his book, “Here Is Where,” already have funded markers at five other locations across the country.

Some are poignant, including one marking the sinking of the Sultan­a ship near Memphis, killing 1,800 Union soldiers on their way home after the Civil War. Another, in North Carolina, honors Jack Johnson, the first black heavyweight world champion, who died in a car crash after he drove away angry when he was denied service at a diner and a white ambulance service refused to take him to a hospital.

Others are pure fun, like the Washington Marriott Wardman Park, where poet Langston Hughes was “discovered” while working as a busboy, and the Hilton Hotel in Manhattan, where the first cellphone call was made by its inventor.

Carroll has at least three more plaques in the works — one honoring the inventor of embalming, another in the name of an American killed in the Bay of Pigs invasion of Cuba and another for a woman who barricaded herself in the barracks at the Alamo to thwart developers.

Carroll said he looks for places where something happened with national implications but has been effectively ignored — in some cases, for good reason. He said: “It’s not enough to be the second-oldest hotel in Texas.”

“I want to show the full scope of American history in unmarked places. It’s all around us. Even in an age of GPS, when we think everything can be found, there are a limitless number of places to be discovered.”

As of Wednesday, there was one less.