I have written about changes in kitchen appliances and other changes in the last sixty-five to seventy years. Just as radical were the rules and the way ladies must conduct themselves to maintain a spotless reputation. You can realize how lenient the rules are today.
First of all, no lady ever wore a sleeveless dress or blouse. There must be a sleeve at least down to the elbow. OF course, no lady wore a dress too tight or cut too low in the front of the neck.
Hemlines varied. During the twenties the short dress appeared with the "flapper" look. That was the era of the "Clara Bow" look, especially in the movies.