I was not born into affluence. I was a lower middle income kid in the Los Angeles Basin, my entire neighborhood was filled with young families, and I watched it every day, I went to PTA meetings with my mom and saw it there, I saw it at grocery stores, movies, restaurants...This is very clear to me. I am not sure what your socio-economic upbringing was, or if your mother was stay at home or a working mom, but it was prevalent in my upbringing. By the way, My grandparents lived in West Seattle, and I visited them often, and it was rampant there as well. The University District, Kent, Renton, Everett, Queen Ann, all bustling with Breast feeding moms. and by the way, the hippy movement started in the early 1960’s, woodstock happend in the Summer of 1969, but the hippy movement is the early 60’s was the beatnik movement, sans Sausalito, the Embarkadero in SF. In the early 1960’s the hippy movement got its air time in the Haight-Ashbury area. Free love, communes, VW Busses...LOL
I think our differing memories have to do with geography. I am older than you and am speaking of my experiences as a parent along with others of my generation. But I’m also speaking of the middle of the country, where the trend may have been later than what you saw on the west coast. Most mothers here were still using bottles in the early 70s.
Definately lower middle income here. No, wait . . . make that lower income, no middle about it. Which was one draw of breastfeeding. Mom gets to eat well and basically feed the kid for free.