What phrase am I looking for?

I’m trying to think of a phrase that exemplifies a series of events and changing attitudes that all come together at the same time and generate the confidence and energy that allows a bigger and consolidated change to occur.

I’m trying to show that in the 1960s the global cultural changes, teamed with changing social attitudes, a series of positive political events and increased support provided the impetus for a minority group to undertake a major political movement and to bring about social change.

I think there is a phrase that will sum this up but I can’t think of it.
Any ideas?