In 1968, Atlantic Ritchfield struck oil in Alaska's Prudhoe Bay. It was a massive strike, the largest oil field ever discovered in North America. Other oil companies joined in and started drilling their own wells. The biggest problem anyone could foresee was how to get 10 billion barrels of oil out of Alaska. Eventually, they agreed that the only practical solution was a pipeline.

Stretching 1,500 miles through the sub-arctic wilderness, the Alaskan Highway was built to defend Americans from threats in the Pacific. The monumental job was assigned to the Army Corps of Engineers. The order was deceptively simple: build a road to Alaska as fast as possible. The Corps rushed over 10,000 men and 250,000 tons of equipment, materials, and supplies north on troop trains.

At 4pm on October 25, the U.S. Army Corps of Engineers closed the last gap of the highway. In fewer than eight months, seven regiments had worked to their utmost limits to clear and lay down an astonishing 1,500 miles of highway. The men who built the highway overcame environmental, technological and physical hardships to complete what many consider one of America's greatest construction projects.

As much as the Corps' officers wanted to punch the Alaskan Highway through in a hurry, dealing with muskeg (swamps of decaying vegetation) and mud drastically slowed things down. By the end of June after three months of work, the Engineers had constructed 360 miles of road. The Army knew it had about four months left to build at least 1,100 more miles before winter arrived.

To clear a path for the road, a lead bulldozer, flanked by two others, tore into the dirt and knocked down trees to create a 60 to 90-foot swath. Behind these front units, the bulk of the regiment widened, straightened, and graded the road, and using the timber at hand, built culverts and bridges.

By September of 1942, the Army Corps of Engineers building the Alaska Highway had struck permafrost—ground that had been frozen for two or more years. After removing the covering vegetation, the frozen ground began to thaw, creating mud. Permafrost wasn’t the only challenge the engineers faced. In October, temperatures began to drop, signaling the start of one of the coldest winters on record.

In 1959, Fidel Castro created the Cuban Institute of Cinematographic Art and Culture (Spanish acronym: I.C.A.I.C.), the agency in charge of film production and distribution. The institute owned and controlled cinemas, oversaw all Cuban film productions and monitored imported films. View an excerpt from an I.C.A.I.C. newsreel of Castro's visit to the U.S.S.R. in 1972.

In 1959, Fidel Castro created the Cuban Institute of Cinematographic Art and Culture (Spanish acronym: I.C.A.I.C.), the agency in charge of film production and distribution. The institute owned and controlled cinemas, oversaw all Cuban film productions and monitored imported films. View an excerpt from an I.C.A.I.C. newsreel on the queue of asylum-seekers in 1980.

In May of 1942, across the rugged sub-Arctic wilderness of Alaska, British Columbia, and Yukon Territory, thousands of American soldiers began one of the biggest and most difficult construction projects ever undertaken -- the building of the Alaska Highway.

High wire artist Philippe Petit electrified New York City -- and the world -- with his early morning walk between the twin towers on August 7, 1974. Here he discusses his preparation for the walk and the high wire journey itself.

Engineer for the World Trade Center, Leslie Robertson discusses architectural aspects of the buildings, including the sculptural quality, close columns and narrow windows, the skin structure, and the comparison to the Empire State Building.

Architectural historian Carol Willis discusses the opposition to the World Trade Center, the public's opinion of skyscrapers, and rebuilding at Ground Zero. Willis was interviewed during the making of Ric Burns' New York: The Center of the World.

Photographer Camilo Jose Vergara discusses the visual impact of the World Trade Center from different perspectives.

Architecture critic Ada Louise Huxtable discusses the options for building at Ground Zero and speaking to the spirit of the location.

Writer Pete Hamill talks about New York before the World Trade Center, the New York economy, what was destroyed to build the towers, and getting used to the World Trade Center.

How did they do it? Find out in this eighteen-minute film, Building the World Trade Center, produced by the Port Authority of New York and New Jersey in 1983 with original footage of the towers under construction.

Journalist William Langewiesche tells the story of one 9/11 survivor. "When he woke up, he was on top of the pile, on top of a huge slab," says Langewiesche.

Three-term mayor of New York City Ed Koch describes a moment on September 11, 2002.

Historian Mike Wallace discusses the US and global interests, Lower West Side business, and the opposition to building the World Trade Center.

President of the World Trade Center Association, Guy Tozzoli, discusses the planning, construction and operation of the World Trade Center.