Women wearing pants

Since the adoption of trousers in Western Europe in Late Antiquity, trousers have been largely worn by men and not by women until the early 20th century.

In 1919, Luisa Capetillo challenged the mainstream society by becoming the first woman in Puerto Rico to wear trousers in public. Capetillo was sent to jail for what was then considered to be a "crime", but the judge later dropped the charges against her.

Women increasingly wore trousers as leisurewear in the 1920s and 30s. In the early 20th century female pilots and other working women often wore trousers. Actresses Marlene Dietrich and Katharine Hepburn were often photographed in trousers from the 1930s. During World War II, women working in industrial work in war service wore their husbands' (suitably altered) trousers, and in the post-war era trousers were still common casual wear for gardening, socialising, and other leisure pursuits.

Similarly, in Britain during the Second World War, because of the rationing of clothing, many women took to wearing their husbands' civilian clothes to work while their husbands were away in the armed forces. This was partly because they were seen as work garments, and partly to allow women to keep their clothing allowance for other uses. As the men's clothes wore out, replacements were needed, so that by the summer of 1944 it was reported that sales of women's trousers were five times more than in the previous year.

In the 1960s, André Courrèges introduced jeans for women, leading to the era of designer jeans.

In 1969 Rep. Charlotte Reid (R-Ill.) became the first woman to wear trousers in the U.S. Congress.

Pat Nixon was the first American First Lady to wear trousers in public.

For a period in the 1970s, trousers became quite fashionable for women. In the United States, this may be due to the passage of Title IX of the Education Amendments of 1972, which declared that dresses could not be required of girls. Dress codes thus changed in public schools across the United States.

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Wikipedia