What is it?: The Keystone XL Pipeline is a system that is designed to carry hundreds of thousands barrels of petroleum that will travel daily from Canada to the Gulf Coast. TransCanada is the company that came up with the idea for the nationwide pipeline. However, there are many debates between whether or not we should finish the building process of these pipelines (UPDATE: the Senate voted against completing the pipelines)
Pros: Pipelines are the least expensive way in the industry to transport oil. Also, it is estimated that the pipelines will create about 42,000 jobs for construction. However, after the completion of construction, only about half of those jobs will be permanent.
Cons: There are environmental concerns due to the crude oil having to be heated and separating the crude from the sand. This concerns environmentalists because they would prefer the oil to be left in the ground, rather than taken from where it lies naturally.
References:
http://www.nytimes.com/2014/11/19/us/politics/what-does-the-proposed-keystone-xl-pipeline-entail.html?_r=0
http://keystone-xl.com/facts/myths-facts/
http://www.npr.org/2014/11/17/364727163/what-you-need-to-know-about-the-keystone-xl-oil-pipeline