Short answers, pulled from the story.
The magical girl genre began in 1966 with the anime adaptation of Himitsu no Akko-chan. This series introduced the first instance of a magical girl using a beauty accessory to transform on a television screen.
The Mahou Shoujo series evolved from simple comedy into a vehicle for social commentary by the early 1970s. Toei Animation produced Mahou Tsukai Chappy in 1972 and Majokko Megu-chan in 1974 to lead this charge.
Sailor Moon arrived in 1991 to redefine the genre by combining transforming hero elements from live-action shows with traditionally feminine interests. The anime adaptation ran from 1992 to 1997 and featured a team of magical girls as the main characters.
The genre took a dark and mature turn in the early 2000s with series like Magical Girl Lyrical Nanoha in 2004. Puella Magi Madoka Magica arrived in 2011 to explore themes of death and the price of magical power.
The magical girl concept found new life in Europe and the United States after spreading beyond Japan. Notable examples include W.I.T.C.H. and Winx Club in Italy, and Totally Spies! and Miraculous: Tales of Ladybug & Cat Noir in France.
Bandai released a cosmetics line based on Sailor Moon transformation items in 2013 for the 20th anniversary of the series. This line was aimed at adult women who grew up with the show and was followed by a life-sized replica of Sailor Moon's Moon Stick.