Chicago has a long history with knitting dating back to World War I when women formed knitting circles to create items for soldiers. During this period, newspapers provided patterns and encouraged readers to knit to support the war effort. In the 1920s-1940s, department stores hired knitting instructors and sold knitting supplies. Knitting grew in popularity in the post-war era as Americans had more disposable income. Stores offered knitting classes through the 1970s to teach patterns and techniques. Chicago was also home to several knitting mills that produced yarn and patterns.