Last night, PBS' American Experience chronicled the building of the Alaska Pipeline, which traverses some 800 miles from Prudhoe Bay to the port of Valdez. Planning for the pipeline began in 1968, but a mountain of legal challenges put off construction until 1975. Two years later oil began flowing south. What kick-started actual construction was the October 1973 Yom Kippur War and the subsequent OPEC oil embargo against the U.S. Relying so heavily on foreign energy sources, Congress figured out, wasn't such a good idea. From American Experience:

July 17: With a vote of 50 to 49, the Senate narrowly passes the Gravel Amendment which declares that the Department of the Interior has fulfilled all the requirements of the National Environmental Policy Act, allowing Alyeska to move forward. Vice President Spiro Agnew casts the deciding vote.

October 6: On the Jewish holy day of Yom Kippur, Egyptian forces attack Israel, while at the same time Syrian troops assault the Golan Heights in a surprise offensive. With help from the United States, Israel succeeds in reversing the Arab gains. The clash will have repercussions for the U.S. oil supply.

Pumps closed due to the gasoline shortage October 17: The Organization of Petroleum Exporting Countries (OPEC) strikes back against the United States and the Netherlands for their support of Israel in the war. OPEC imposes an oil embargo. Overnight, the price of a barrel of oil rises from $3 to over $5. Gas at the pumps will soon rise from 30 cents per gallon to $1.20, and drivers will wait in long lines to fill up their tanks.

November 16: In direct response to the oil crisis, President Nixon signs the Trans Alaska Pipeline Authorization Act into law. Nixon introduces "Project Independence" in a televised speech: "Throughout history, America has made great sacrifices of blood and also treasure to achieve and maintain its independence. In the last third of this century, our independence will depend on maintaining and achieving self-sufficiency in energy."

Some things never change on the independence front.