Where did this style of clothing come from?

Is it still worn today?

This is an example of Hanbok, the traditional style of clothing from Korea (in North Korea, it is called Joseon-ot). These garments were acquired by the Karshner Museum in 1987. The term "hanbok" literally means "Korean clothing." There have been many shifts in hanbok style since it emerged over 1600 years ago, during the Three Kingdoms period of Korean history (57 BCE to 668 CE). Influenced by Confucian dress code as well as northern Mongolian style, it was at this time that the basic hanbok elements took shape: the jacket, or jeogori; the skirt, or chima (for women); and the pants, or baji (for men).

Yes! In the twentieth century, clothing styles in Korea thoroughly Westernized, but hanbok still maintains a special place. Just like in the dress of other cultures, there are hanbok variations for ceremonial and everyday dress, as well as for special occasions. The most common style of hanbok worn nowadays is the style formalized in the Joseon period, which lasted from 1392 to 1897. During that era, commoners were only allowed to wear white or light-colored cotton hanbok, while brighter and more colorful variations and flashier textiles were reserved for court officials and the upper classes. In 1996 the South Korean government proclaimed a nationwide Hanbok Day, to encourage Koreans to embrace the traditional clothing. Modern fashion brands have incorporated elements of the traditional designs into new styles, and although opinion in Korea is divided regarding the new designs, hanbok is still very much a part of the national conversation.

Links to learn more...

(Korea.net) Hanbok Day brings new styles
(VisitKorea.or.kr) Hanbok: Traditional Korean Clothing
(AntiqueAlive) Traditional Korean Clothing