Bill McKibben, considered a leader of the Keystone pipeline protests and founder of 350.org, said in response to Obama's decision, "This is a victory for Americans who testified in record numbers, and who demanded that science get the hearing usually reserved for big money."
McKibben was among thousands of protestors assembled around of the White House at two rallies in August and November to encourage President Obama to reject the Keystone pipeline. November's rally saw an estimated 10,000 people surrounding the White House.
A number of celebrities also spoke out against the Keystone pipeline. Actor Mark Ruffalo told HuffPost at the Keystone pipeline protest in front of the White House in November, "We invite the president to make good on his promises of a real renewable energy policy for the United States."
Concurring with the State Department, Obama said the "rushed and arbitrary [approval] deadline" imposed by Congress "prevented a full assessment of the pipeline's impact." The president stressed that his rejection does not prevent re-application by TransCanada or exploration of similar projects.
Canadian officials were irked by Obama's decision, but maintained their confidence that oil from Alberta's tar sands will be exported to Asia, if not south to the U.S. through the Keystone pipeline, reports The Globe and Mail.
Below, check out images from the Keystone pipeline protests in 2011.