The United States was less than a decade old when Congress - still based in Philadelphia - debated what the nascent nation might put on its currency. The final decision was a simple one: Every coin, the resulting Coinage Act of 1792 required, had to have an "impression emblematic of liberty."

The U.S. Mint, created by that act, is 225 years old this year, and over the last two centuries an image of Lady Liberty has graced coins both commemorative and circulatory. But she's typically portrayed as a white woman - that is, until this year.

For its anniversary, the mint is producing a special gold coin, marketed to collectors and with a face value of $100, with a profile of Liberty depicted as an African American woman.

On the coin, Liberty looks to the left, her chin set, her hair swept back, the slightest smile on her lips. On her head is a crown of stars.

Elisa Basnight, the chief of staff at the mint, called the design "groundbreaking." The federal advisory committees that recommend coin designs had expressed a desire for more diversity on the country's coins, she said.

"Our hope is that this coin really gets people thinking and talking about what liberty looks like and represents to them," she said. "Lady Liberty, depicted in coinage throughout the years, is modeled after our society's continued evolution - and as we as a nation continue to evolve, so does its representation."

The 1-ounce coin, unveiled at the Washington mint Thursday afternoon, is struck in 0.9999 fine 24-karat gold. With the price of gold currently sitting at $1,200, the coin will sell for a lot more than its face value when it is offered this spring. The mint sells another 1-ounce coin in 22-karat gold for $1,510.

The new coin is a collector's item. But the country's currency as a whole is slowly diversifying. Last year the Treasury announced plans for Harriet Tubman to replace Andrew Jackson on the front of the $20 bill.

The decision was not without controversy, and neither is this one, at least in the coin-collecting world.

"If you were a young black woman happening upon the Coin World Facebook page, how would you feel if you saw so much vitriol directed at a coin design showing someone who might look like you?" wrote William Gibbs, managing editor of the aforementioned coin-collecting magazine, after the coin design leaked. "You probably wouldn't stick around."

Justin Kunz, the artist who designed the new depiction of Lady Liberty, designed a similar coin in 2015 and said that, this year, he wanted to "put forward the possibility of having a Lady Liberty who's ethnically different than what we see in the past."

He collected coins as a kid and fell into the coin business after the mint put out a call for designers in 2004. It took him until 2008 to get a design chosen for a coin.

"It's still exciting," he said, laughing. "I get a real charge out of it - it hasn't become boring."

Though the higher-ups who run the mint moved to Washington more than 200 years ago, coins are still produced in Philadelphia. The original mint building was the first federal building constructed per the Constitution, and Rittenhouse Square is named after its first director. The newer mint building on Independence Mall, built in 1969, still makes coins (and gives tours). 215-854-2961 @aubreyjwhelan