Ancient Use
An article on the National Yo-Yo Museum site states that the first yo-yos probably came from ancient China, and it is likely that they spread from there to other parts of the world. A Greek vase painting from 500 BC shows a child playing with a yo-yo, and an 18th century box made in India is decorated with a painting of a girl and her yo-yo.
U.S. Yo-yos
The first mention in the U.S. of yo-yos was in 1866, when an "improved bandalore" was patented. In 1916, a "Scientific American" article about Filipino toys mentioned the yo-yo and credited its name to the Filipino word for "come-come" or "to return," according to the National Yo-Yo Museum.
First Company
America's first yo-yo company was begun in 1928 in California by Pedro Flores, a native of the Philippines. Flores' yo-yos were hand-carved from one piece of wood. Their design was unique in that the string was not tied to the axle, but looped around it. This allowed the user to not only move the yo-yo up and down the string, but to perform many tricks.
Duncan Yo-yos
Businessman Donald F. Duncan saw the potential in mass marketing this "new" toy, and purchased Flores' yo-yo company. Duncan's advertising campaigns included popular yo-yo trick demonstrations and contests. In 1932, he received a trademark for the word "yo-yo," preventing his competitors from using the name (the ruling was later overturned). When the company went bankrupt in 1965, the Flambeau Plastics Company, which had been manufacturing Duncan's plastic yo-yos, purchased the well-known Duncan name and continued producing the toy.
Innovations
Duncan's Classic Line includes the Imperial and the Butterfly for beginners, while the Hard Core line of yo-yos are designed for competitors and professionals. The DeLuxxe Line includes the Freehand MG, marketed as "the perfect yo-yo." Made of forged magnesium and featuring a stainless steel and silicone nitride ball bearing axle, the Freehand MG sells for $400 in 2010.
Space Experiments
The yo-yo was first taken into space on the Space Shuttle Discovery in 1985 as part of NASA's Toys in Space project. Experiments using the yo-yo in microgravity showed that the yo-yo could be released at a slow speed, but without the downward force of gravity, it immediately rebounded up the string and did not "sleep," or spin against the loop. A yo-yo was also used for experiments on the Space Shuttle Atlantis in 1992.