Action figures were originally toys that were ready for “action,” because they were more flexible than similar-sized dolls. Designed with multiple joints, G.I. Joe could wage war, Jane and Johnny West could ride their horses and Evel Knievel and Derry Daring could perform motorcycle stunts.

With the introduction of Star Wars action figures in 1978, these toys became smaller and less flexible. Today, action figures are still meant for action-oriented play, but they’re also something many people collect and display. Here’s how the popular toys have evolved (and shrunk) over time.

In 1959, the Mattel toy company introduced a new doll named Barbie. The 11.5-inch toy quickly became a hit among American girls, and Mattel capitalized on this popularity by marketing different types of Barbie dolls with interchangeable clothing and accessories.

Barbie was a toy that encouraged children to want more toys. Once kids had a Barbie, they wanted to buy her boyfriend Ken (introduced in 1961), her Dreamhouse (1962) and her little sister Skipper (1964)—not to mention more clothes for Barbie. Don Levine, vice president and director of marketing at the rival toy company Hasbro, was interested in developing a similar toy Hasbro could market to boys. He helped convince the company to buy inventor Stan Weston’s idea for a military doll. In 1964, Hasbro released that toy as G.I. Joe.

Drawing inspiration from wooden artists’ mannequins, Hasbro designed G.I. Joe with moveable joints, giving the toy 19 points of articulation. This made the nearly 12-inch toys a lot more flexible than Barbie. To distinguish G.I. Joe from dolls—which companies mostly marketed to girls—Hasbro marketed G.I. Joe to boys as an “action figure.”

The original G.I. Joe was a U.S. Army soldier, but Hasbro soon released more versions of the toy: a G.I. Joe Navy sailor, Air Force pilot, U.S. Marine and NASA astronaut, as well as a female “G.I. Nurse Action Girl.” In addition to these white action figures, Hasbro released a Black G.I. Joe Army soldier. Like Barbie, G.I. Joe had interchangeable clothes, weapons, vehicles and other accessories; and the purchase of one toy encouraged the purchase of more.

By 1966, G.I. Joe accounted for nearly two-thirds of Hasbro’s profits. However, as American support for the Vietnam War declined, so too did G.I. Joe’s popularity.

“Around that time, a lot of people were arguing that their kids should not be playing with war toys,” says Michelle Parnett-Dwyer, a curator at The Strong National Museum of Play in Rochester, New York.

In the early 1970s, Hasbro released a new version of G.I. Joe that had a beard, a less explicit connection to the U.S. military and “Kung Fu Grip” (which just meant you could bend his hand). Still, the new toy line was not particularly popular, and Hasbro ended it 1978, the same year that the first Star Wars action figures came out. These new toys, based on the popular movie, would prove to be a watershed moment in the evolution of movie tie-ins and of action figures.

Soon after G.I.’s release in 1964, rival toy companies developed their own action figures aimed at both boys and girls. In the mid-60s, Mattel released Major Matt Mason, an astronaut who lived on the moon, and the Marx toy company released cowboy Johnny West and cowgirl Jane West. Marx also released a female action figure based on the TV show The Girl from U.N.C.L.E.—a type of marketing tie-in that would become more common in the coming decades.

During the 1970s, the Mego toy company began selling action figures based on characters in comic books, TV shows and movies, along with a G.I. Joe knockoff dubbed “Action Jackson.” These eight-inch toys were smaller than previous action figures, and capitalized on the existing popularity of DC and Marvel comics, the “Star Trek” TV series, and the Planet of the Apes movies. However, these toys suffered from being made with a type of bendable material that deteriorated or melted over time, Parnett-Dwyer says.

This may have been due to the 1970s oil crisis, which increased the price of plastic and led companies to make toys with less durable material. This was the case with the new G.I. Joe, whose arms were more likely to fall off. Many ‘70s action figures were also smaller than G.I. Joe or Barbie. In addition to Mego’s eight-inch action figures, Ideal Toys’ Evel Knievel and Derry Daring action figures stood around seven inches tall. (The Evel Knievel toy was based on a real-life stuntman; Derry Daring was possibly inspired by stuntwoman Debbie Lawler).

Before Star Wars premiered in 1977, director George Lucas and 20th Century Fox approached Mego about producing Star Wars action figures, but the company passed because it didn’t expect the movie to do very well. Instead, the Kenner toy company acquired the license. In 1978, Kenner released the first Star Wars action figures: Luke Skywalker, Princess Leia, Chewbacca and R2-D2.

At 3.75 inches tall, these action figures were on the smaller side, making them cheaper to manufacture amid the ongoing oil crisis, and cheaper for people to buy. They also allowed the company to design some of the film's vehicles, like Han Solo's Millennium Falcon, at a scale that wasn't too big for children to play with. The movie’s success made these Star Wars toys incredibly popular, even though, with only five points of articulation, they weren’t as flexible as previous action figures. Over the next several years, Kenner expanded the number of characters available from four to close to 100 to include more characters from the original movie, as well as its sequels The Empire Strikes Back (1980) and Return of the Jedi (1983).

The original Star Wars line, which ended in 1985, had a major influence on the action figure market. Smaller action figures became popular collectibles, and action figures based on movies, TV shows and comics proliferated. When another new G.I. Joe line debuted in the early ‘80s, these action figures were 3.75 inches tall, and had a TV show and comic book tie-in to promote them.

Since the 1980s, action figures have expanded beyond the kind of media tie-ins associated with children to include basically anyone or anything. Today, you can still buy—and collect—action figures based on the new Star Wars movies and TV shows, but you can also buy action figures based on shows like "The Golden Girls," or even based on historical figures ranging from Ludwig van Beethoven and Benjamin Franklin to Barack Obama.