If you wanted to be considered even remotely good looking in early 1900, it was important for you, as a woman, to follow the fashion expected at the time. And the fashion expected in early 1900 meant tiny waists, emphasized hips, and protruding posteriors.
Corsets were an absolute must throughout early 1900 and earlier. Assorted corsets offered various series of folds, curves, and contortions for new and upcoming silhouettes. The timeless elegance of the corset, was true to fashion as it reduced the waist with beautiful tight lacing.