During the 1930s and 1940s the company became the leading manufacturer of work clothes in the US. In 1944, the Lazy "S" became the official Lee back pocket. A flood wiped out Lee's Kansas City distribution center. It ruined the entire stock of merchandise, except the Buddy Lee dolls, which floated. In 1954, Lee expanded into casual wear. During the 1960s the company expanded to 81 countries and in 1969 was acquired by VF Corporation, becoming a brand. Denim made the crossover into the fashion market and bell bottoms are welcomed with open arms by Vietnam protesters. Lee aired its first television advertisement, which promoted Lee western wear.
In the 1970s Lee shifted its focus from the workwear business and began catering to fashion cycles. Lee created an all-new fit for women under the Ms. Lee label. A youth wear line for boys and girls was introduced. In 1996 started Lee National Denim Day as part of National Breast Cancer Awareness Month. Working with the Entertainment Industry Foundation, Lee National Denim Day has raised over $75 million to help fund breast cancer research programs.