It’s been almost two years since CaShawn Thompson told the world that black girls are “magic.”

But not everyone has gotten the message.

Not so long ago, mainstream news outlets published pieces saying that Oscar-nominated actress Viola Davis and tennis superstar Serena Williams don’t fit the “classic” or “ideal” images of beauty and femininity. Feminista Jones, a prominent feminist writer, has said that she is “attacked on a daily basis” online with derogatory and threatening messages.

But the negativity extends beyond celebrities and public figures, affecting many black women of all ages. Michelle Obama was frank about this in a speech at the “Black Girls Rock!” awards in March, when she said that young black girls often heard “voices that tell you that you’re not good enough, that you have to look a certain way, act a certain way; that if you speak up, you’re too loud; if you step up to lead, you’re being bossy.”

Thompson, who tweets at @thepbg, however, is inspired by the black women who persevere despite this adversity. For her, their achievements are like “magic.”

“I say ‘magic’ because it’s something that people don’t always understand,” Thompson said in a phone interview with The Times. “Sometimes our accomplishments might seem to come out of thin air, because a lot of times, the only people supporting us are other black women.”

With that in mind, Thompson began to use the hashtag #BlackGirlsAreMagic in 2013, to speak about the positive achievements of black women. Since then, the hashtag has spread widely. Calling it “viral” might risk misinterpretation, as this isn’t a flash in the pan that disappears once the moment is gone. Instead #BlackGirlsAreMagic has gradually been gaining popularity.

Since its inception, the hashtag has been used for just about everything that shows positive images of black women. Tweets using the tag range from admiration for tennis stars Venus and Serena Williams or "Selma" director Ava DuVernay, to proud friends reposting pictures of college graduates from their hometowns.

In January 2014, Thompson decided to use the site Teespring.com to make a few shirts for her circle of friends. She and a friend created a simple logo featuring the words “Black girls are Magic,” added a few sparkles and put the T-shirts online. She had hoped to sell 30 shirts, but in her first run, she sold more than 300.

“I underestimated how many people would connect with the message,” she said. “I’ve sold about 3,000 shirts up until this point today.”

The shirts also have celebrity appeal. Willow Smith, the daughter of Jada Pinkett Smith and Will Smith, has posted a snapshot of herself sporting a cropped “Black girls are Magic” tee on Instagram. "Hunger Games" star Amandla Stenberg has also posted an image of herself wearing a logo hooded sweatshirt.

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Many who are active on social media buy shirts for themselves, but Thompson has been more impressed by people who give the shirts as gifts. “I’ve seen people buying shirts for their daughters, their nieces, their goddaughters,” she said. “They want to encourage young girls too.”

But the popularity of the hashtag, which Thompson calls a “movement,” has had some unintended consequences. On Monday, a recently launched online fiction magazine called Black Girls Magic Magazine became the target of criticism when some social media users accused the founder, Kenesha Williams, of plagiarizing Thompson’s work. The name of the site, as well as the logo, were similar to Thompson’s. Williams wrote later that she had seen the phrase “floating in the ether,” but she did not realize that Thompson had created it.

After a brief public uproar on Twitter, the two spoke via phone, and the owner of the magazine agreed to change the name and logo of the magazine. Thompson says that she is considering copyrighting the phrase, her logo or both. She says that she doesn’t want to prevent people from sharing it, but she does want to “make sure it’s being used correctly, in a respectful way.”

At the same time, Thompson does not seem particularly concerned with people knowing that she is the originator of the hashtag.

“People know the logo and the movement, but they might not necessarily know me. This started out as just my circle of friends, but it’s grown much larger than that,” she said. Aside from celebrity sightings, Thompson says that she regularly gets emails and tweets from people telling her that they’ve seen her tees all over the country, and as far away as Australia. “My daughter says that she sees people wearing the shirts on her college campus. She tells them her mom started it, but they don’t believe her,” she said with a laugh.

“But that’s fine. I wanted people to connect with this, and I’m so happy that they did. I wanted it to spread.”

Follow me @dexdigi for more on the intersection of culture and the Internet.