We did not live here in 1984, but the other day my significant other found in the trash a framed poster for the 1984 World Expo. We have searched the Internet and scoured through official expo documentation and can't find it. It looks legit and has the graphic of the expo's logo, but I don't know if there were many different posters or if this is distinguished in any way.
One of the problems associated with the 1984 Louisiana World Exposition in New Orleans was poster proliferation. There were posters depicting water goddesses, waterfowl and water sculptures. There was even a poster depicting a pelican, an armadillo, a fish and a man wrestling an alligator — all against a background of water.
The New Orleans World's Fair opened to the public on May 12 and ran throug Nov. 11, 1984. Exposition officials authorized at least a dozen official posters, and the market was swamped.
Two businesses — ProCreations Publishing Company and DKR International — were licensed by the fair to turn out six posters each, but eventually produced more. Artists could sell posters they designed and include the official fair emblem on them if they could get either of the licensed companies to distribute them.
One of the most popular World's Fair posters was The Water Goddess by Hugh Ricks. Issued in 1982, 5,000 prints were produced, and Ricks signed 1,000 of them. In 1984, The Water Goddess poster was selling for $300 in art galleries. Another popular poster depicted the Wonderwall. Charles Moore, the architect who designed the whimsical wall, created sculptural depictions of water themes both real and mythical. About 40,000 copies of that poster were made.
You could take your poster to a gallery and have it appraised.