Footie pajamas — sometimes called footed pajamas or onesies — have their origins in the late 19th century, when one-piece sleeping garments called union suits were invented in New York. Union suits were originally designed for women, but quickly caught on among men. Originally, they were made of red flannel fabric and featured buttons in the front and a flap in the back. During World War II, Winston Churchill wore siren suits (so named because he could easily put them on during air raids). They closely resembled the design of a traditional onesie without the feet, although they were made from materials not usually associated with sleepwear. In the 1950s, footie pajamas became popular for children. A man named Wiley Denton, a worker at the Michigan Central Woolen Company, created the first mass-produced footie pajamas for children, which he sold under the name “Dr. Denton’s Blanket Sleepers.” They were a huge hit. In 1998, a company called JumpinJammerz began manufacturing footie pajamas for adults. Reportedly, they were originally meant to be a costume gimmick for founder Steve Pandi’s rock band. Over time, the popularity of footie pajamas for adults increased, and several TV shows featured characters wearing them. Many celebrities also became devoted fans, including Ryan Gosling and Brad Pitt. Today, footie pajamas are available in a wide variety of patterns, styles, and sizes for kids and adults alike, and they are often favored in the winter due to their ability to keep the wearer warm and cozy.