The paper plane has a shockingly long history.
Kids were having fun launching paper into the air decades before the Wright brothers had their first flight in 1903. They just called it by a different name. And its original design looked strikingly similar to the airplanes we make today.
"Paper darts" were the best way to have fun with flying paper
As early as 1864, kids were flying "paper darts" that looked like what we call "paper airplanes" today. During the Civil War — yes, kids flew paper airplanes during the Civil War — Every Little Boy's Book gave kids instructions for making a paper dart that "makes a graceful curve in passing through the air." In 1881, as instructed in Cassell's Book of Sports and Pastimes, kids were told how to make a paper dart using "a piece of good stout paper." The instructions reveal a design that looks exactly like the familiar paper airplane.
People even used paper darts the same way kids use paper airplanes today: to be annoying. An 1881 description of the New York Stock Exchange noted an unusual punishment: "to throw a paper dart or ball at a member during the session of the Board is to incur a fine of ten dollars." Naturally, people threw paper darts at teachers, too: an 1889 story recalls the many times "a paper dart has glided noiselessly down the room, amidst the suppressed applause and smothered hilarity of the students."
Sometimes, as today, kids made modifications to the classic paper dart model. Occasionally they'd wedge a used pencil into the design to give it heft, or make a longer version, like this one from 1909:
But for all intents and purposes, the "paper dart" was the "paper airplane" — the only thing that changed was the name.
It took a surprisingly long time for "paper airplanes" to replace "paper darts"
The term "paper aeroplane" appeared in the 1890s, before successful powered flight, but those paper airplanes looked a lot different from the ones today. Many people imagined that manned flight would require flapping wings, so early "paper aeroplanes" copied that model. At the time, the paper plane was seen not as an extension of the paper dart, but as a way for kids to imitate the winged flight that seemed to be the future:
Scientific American designed an aeroplane/paper bird in 1894 that had a birdlike appearance:
These overly literal models of planes helped "paper darts" endure. The marvelously titled What Shall We Do Now?, a children's book, proposed a perfect paper airplane in 1900 — but it was still called a paper dart:
References to paper darts extend well into the 20th century, presumably in part because people who grew up with paper darts had no reason to change. Though the term "paper aeroplane" was around much earlier, it wasn't the default term, probably because the paper darts just didn't look like real planes.
A 1933 issue of Popular Mechanics hints at what finally helped the paper dart become a paper airplane: the development of new plane shapes. The headline to that 1933 piece was "Airplane Like Dart Has Lengthwise Wings."
The plane was just a prototype, but soon reality — and paper planes — caught up.
Sleek new airplanes become a fixture, and paper darts finally became paper airplanes
By the 1950s and '60s, it became much easier to associate the shape of a paper dart with an airplane, thanks to second-generation fighter jets. These jets had the aerodynamic shape of a paper dart, and as a result, paper darts finally started to look like real airplanes — and the "paper plane" metaphor finally made sense. Though there are numerous references to "paper planes" before the rise of the fighter jet, it took the rise of the sleek new plane to kill the "paper dart" and make "paper plane" the default term.
Today, paper planes are studied as seriously as real planes: they're art objects designed to imitate real planes and optimized to achieve world records. But they were around years before the objects they're now named for. It makes sense. Kids always loved throwing paper, even during the Civil War. It just took a while for engineers to catch up to their designs.