In the front-end world Sproutcore never made a huge splash and was not used by many companies outside of Apple. Sproutcore was frequenly blogged about and critically popular, but not used by a large amount of developers and companies in any way Backbone/Angular/Ember are... or even the way early versions of Rails were used.
Backbone.js was the starting point of the huge JS MVC community that exists today. Primarily due to it's simplicity and Rails-esque nature, where as Sproutcore was unwieldily and enterprise-software-esque until work on Ember started.
Rails had many early predecessors as well but Rails was the one that did it right, and spurred that style of framework's popularity.
Fair enough, I remember it that way too. I was only looking to clarify what I read in your original post as indicating that backbone.js was the first one. I agree with you that it was the first highly popular framework.
Angular's history is also similarly older - it was created in a rough form in 2009 for data binding purposes. The creator used to work on Adobe Flex, so Angular probably owes much of its design from that.