The USDA said they had used Wakanda when testing the system behind the tracker and had forgotten to remove Black Panther's home country.

"Over the past few weeks, the Foreign Agricultural Service staff who maintain the Tariff Tracker have been using test files to ensure that the system is running properly," Mike Illenberg, a USDA spokesman, said over email. "The Wakanda information should have been removed after testing and has now been taken down."

Francis Tseng, a fellow at the Jain Family Institute, first noticed Wakanda listed as a trade partner Wednesday morning when researching how trade deal tariffs affect food distribution and hunger in those countries. While looking for a resource that examined existing trade deals, he came upon the USDA tariff tracker and was instantly stunned by his discovery.

“I definitely did a double take,” he said. “I Googled Wakanda to make sure it was actually fiction, and I wasn’t misremembering. I mean, I couldn’t believe it.”

Wakanda is listed as a US free trade partner on the USDA website?? pic.twitter.com/xcq1OFTIPh — Francis Tseng (@frnsys) December 18, 2019

There were hundreds of data inputs for Wakanda, a nation that first appeared in the July 1966 Marvel comic Fantastic Four #52. Different commodity groups offered on drop-down menus range from fresh vegetables and unroasted coffee beans to essential oils and livestock.

Each commodity group had separate entries that provide details on the tariffs for each product.

Yellow potatoes had to maintain a “0.5 cent/kg” base rate when shipped in from the fictional East African nation, while frozen Chinese water chestnuts were tariff free if the U.S. decided to import them from Wakanda. Cows were also tariff free.

The website notes, however, that the “information displayed is not official and should only be used as a general reference. Each importing countries customs office maintains the right for final determination of tariff treatment.”

It appears that Wakanda was listed as a free trade country with the U.S. sometime after June 10, according to the Internet Archive.

Marvel did not respond when asked about the fictional nation's apparent temporary trade agreement with the U.S.

Tseng said earlier in the day he was stumped by the discovery.

“I was trying to figure out whether this is someone at the USDA making a joke or if it’s a developer who accidentally left it in, but I’m not sure,” he said.