What would you say were the biggest influences of buddhism, or eastern philosophies in general, on 1960's american society?
Good question and probably the works of Alan Watts and some others helps formulate the existentialistic questions of the age such as -who am I? But with some direction for answering which was loose enough to allow self discovery. Of course Trungpa through his association with the Beat authors such as Ginsberg I'm sure lent a tone of openness sanctioned by religion which was not previously noted.
Alan Watts and his book "The Way of Zen" in the 1950's, is usually creditted for being the first popular work on the subject. It just kept growing from there.