There are 3 cultural occurrences that are closely associated with Boomers that didn't originate with Boomers or weren't majority Boomer things initially. The reason that they are associated with Boomers is that they were the largest generation that came after these things happened and they adopted the trends that came out of these.
1. The birth control pill and the growth in use of contraception.
The birth control pill launched in 1960. In 1960, the oldest Boomers were 14 years old. During most of the 1960s, the women using birth control pills were women who were members of the Silent Generation (1930s-early 1940s births). It really wasn't until the 1970s that more of the women using the birth control pill were Baby Boomers.
Condoms had been around for many decades prior to the 1960s. There was some growth in condom use in this time, but I don't think condoms became more of a thing until HIV/AIDS in the 1980s. Later Boomers and early Gen X were more affected by this.
The original use case for birth control was for established, monogamous couples to delay a pregnancy. This could be seen in this fictional representation of the era from the pilot episode of "Mad Men" taking place in March 1960. The Peggy Olson character (born 1939 - Silent Generation) goes on birth control soon after getting a secretarial job at an advertising agency. Peggy is sent by co-worker and manager of the secretarial pool Joan Holloway (born 1931 - Silent Generation) to get birth control.
While the scene is fictional, it does touch upon relevant parts of the birth control experience of the earlier part of the 1960s and how it started in the Silent Generation.
2. Woodstock
Woodstock happened in August 1969. At that time, the oldest Boomers were 23 years old. While I think there were many 18-23 year old attendees of Woodstock who were Boomers, more of the attendees of Woodstock were 1939-1945 late Silent Generation born people. A lot of the Woodstock musicians were late Silent Generation, like Joe Coccker, Jimi Hendrix, Joan Baez, and the members of Creedence Clearwater Revival. Carlos Santana and his band members were actual early Boomers.
Woodstock was held in a rural area in Upstate New York, only about 100 miles from New York City. The people who attended Woodstock generally lived within driving distance of the southern part of Upstate New York. These were mainly Northeasterners (Boston and New York-New Jersey area people). People who lived in places Texas, Florida, and California did not have the ability to attend Woodstock.
A greater percentage of the population of the US lived in the Northeast, Pennsylvania, and Ohio in 1969 as compared to 2000-present. Florida and Texas were smaller states back then. California had a significant population in 1969.
A lot of Boomers were too young and lived too far away to attend Woodstock.
The free love and promiscuous spirit of Woodstock did influence Boomers into the 1970s though. There is a relationship between free love, promiscuity, and the next item.
3. No fault divorce
California became the first US state to have liberalized, no fault divorce laws starting in 1969. During the 1970s, most other US states liberalized their divorce laws following the model of California.
In the 1969-1975 era, most Boomers were either too young to be married or were in the earliest stages of marriage and yet to be unhappy enough to want to divorce. The earliest people who got divorced under the new, no-fault divorce laws were people from the Silent Generation.
Boomers didn't start becoming the biggest divorce group until the 1980s, when more of them were old enough to be married and want to be divorced.
