In 1959 I was sixteen years old and still a virgin. My primary reason for remaining a virgin was fear of pregnancy. Also, girls who were known to not be virgins had very bad reputations and were often called vulgar nicknames, and I didn't want to be condemned to a bad reputation. But it was mainly fear of pregnancy that stopped me from losing my virginity.
Virginity was very important in the 1950's. When dating, all of the guys tried to get the girls to sleep with them, trying seduction, force and/or sometimes begging. But almost every guy wanted the girl to be a virgin when he succeeded in seducing her. Virginity was valued, and parents would want their son to bring home a girl who was "pure" and "inexperienced". Girls were expected to remain virgins until they married.
This wasn't always realistic and of course not all girls were virgins. Many girls were very troubled about the double standard that was prevalent at that time. Even the girls who were not virgins, still claimed to be virgins if they thought they could get away with it. The test would be if the girl had some bleeding when she finally "lost her virginity". Girls would come up with all kinds of excuses about why they didn't bleed when their hymen broke. One of the more popular excuses was the girl injured herself as a child, usually on a bicycle. Girls came up with all kinds of creative excuses that were tricky and very difficult to pull off. But if the girl pulled it off, and her "boyfriend" believed she was a virgin, she would be held in higher esteem.
I personally knew many girls who were virgins over and over again.