"That group of people united in pursuit of a cause, and basically the result was greater than the sum of the parts. There was a chemistry that was formed," Kranz said."
The Cold War undoubtedly helped, though my impression (I am not American) is that there was a greater sense of social cohesion back then (that did not include minorities).
Assuming social cohesion is a public good, i.e., public policy should help bring it about without having to engineer a cold war, how would a society go about it? National service?