Grist posted the history:
Everyone is talking about President Obama’s decision to reject the Keystone XL pipeline proposal, but he’s not actually the hero of the story. The Keystone decision is the culmination of a startlingly successful grassroots activist campaign that defied the odds and convinced the Obama administration to change course against building a major piece of fossil fuel infrastructure. Here’s how it came together, as recounted by a few of the key players.
Read the whole story here.