1920's
This was the era of the flat-chested, slim-hipped flapper girls. 
Ideal Then:
1890's
Women of this time were ideal with "a plump body, pale complexion, [which] represented wealth, an abundance of food and a refined indoor lifestyle"(Region of Peel). They were also looked at as lazy, sexual playthings.
This was the era of the flat-chested, slim-hipped flapper girls.
50's and 60's
The ideal image of this time was the Full figured shapes like Marilyn
Monroe. The 'ideal' height was 5'8 and 132 lbs. Monroe was a size
14, and in today's world, she would be considered chubby.