I came across an interesting article charting the rise and fall of the girl group sound: http://www.smithsonianmag.com/issues/2007/february/girlgroups.php?page=1
Although there were girl groups in the 50s such as the Chantels and the Bobbettes, it wasn't until the Shirelles Will You Love Me Tomorrow that the genre really made an impact on me. That was in January 1961, and in the same month Angel Baby by Rosie and the Originals also made an appearance in my top ten. The Shirelles continued to produce a string of great records during the next couple of years, including Dedicated To The One I Love, What a Sweet Thing That Was and Baby It's You, and for a while they seemed to have the field almost to themselves. But a trend was beginning and by year end the first of the great Motown girl groups, the Marvelettes, had hit with Please Mr Postman.
The following year, 1962, I became aware of the Crystals, whose early records Uptown and There's No other Like My Baby, showed little of the Phil Spector Wall of Sound, and there was a hint of what was to come with Little Eva's The Loco-motion. But the girl group sound - usually featuring rather innocent tales of teenage angst - really took off with He's a Rebel by the Crystals, Don't Hang Up by the Orlons and the Exciters' Tell Him. By now we were into 1963 and the girl group sound was becoming firmly established. Among the records to make my top ten in that year were further singles by the Crystals and the Exciters, He's So Fine by the Chiffons, Chains by the Cookies, It's My Party by Lesley Gore, Easier Said Than Done by the Essex, Wonderful Dream by the Majors and My Boyfriend's Back by the Angels. Of course Motown was also getting into its stride, with further girl group hits by the likes of the Supremes, Martha and the Vandellas, the Velvelettes and the Marvelettes. And Phil Spector's influence had spread still wider with classics by the Crystals, the Ronettes and Darlene Love. Red Bird produced a number of classic girl group records from the Shangri-Las, the Jelly Beans and New Orleans' own Dixie Cups among others. By 1965 the trend had peaked. No doubt the British invasion had had the same stifling effect on girl group records that it had on many other forms of American pop music.
But now it seems the film Dreamgirls has reawakened awareness of the girl groups - and not before time. It may have been a short lived trend, but it has been revived more than once and the early examples of the genre still sound brilliant today. It's worth getting hold of the book Will You Still Love Me Tomorrow by Charlotte Greig if you come across it. Not an exhaustive history of girl groups, but worth a read.