The project requires presidential approval but Keystone is a major challenge for the Obama administration in an election year because of opposition from environmental groups.
TransCanada has argued for months that the Keystone XL pipeline from Alberta to the Gulf Coast is vital to the United States because it will provide energy security and much-needed jobs.
The Calgary-based company says Keystone XL would create 13,000 construction jobs and 7,000 manufacturing jobs.
TransCanada says it has contracts with over 50 suppliers across the country, some of them in important political battlegrounds for this year's elections.
It says there are manufacturing locations for its equipment in Texas, Missouri, Pennsylvania, Michigan, Oklahoma, South Carolina, Indiana, Georgia, Maryland, New York, Louisiana, Oklahoma, Minnesota, Ohio, Arkansas, Kansas, California and Pennsylvania.