This Day In History takes us back to June 11th, 1979, Hollywood lost its best cowboy everJohn Wayne. Nick named the "Duke" after the family dog, Wayne wasn't always the tough guy he played on screen, but a family man. Learn about his legacy in this great clip about the actor.

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See what happened in history on November 6 in this video of This Day in History. In this day in 1512, Hernan Cortez captured Mexico City from the Aztecs, a powerful civilization of Mexico at the time. On November 6, 1861, Jefferson Davis was elected the first President of the Confederacy. He was also its last president. On November 6, 1961, East Germany sealed off the boarders between West Berlin and East Berlin. This was done to stop the refugees from going west. Lastly, on November 6, 1962, the United Nations condemned the Apartheid of South Africa. Their racist ways led to decade long sanctions on South Africa.

At 4 a.m. on March 28, 1979, the worst accident in the history of the U.S. nuclear power industry begins when a pressure valve in the Unit-2 reactor at Three Mile Island fails to close. Cooling water, contaminated with radiation, drained from the open valve into adjoining buildings, and the core began to dangerously overheat. After the cooling water began to drain out of the broken pressure valve on the morning of March 28, 1979, emergency cooling pumps automatically went into operation. Left alone, these safety devices would have prevented the development of a larger crisis. However, human operators in the control room misread confusing and contradictory readings and shut off the emergency water system. By early morning, the core had heated to over 4,000 degrees, just 1,000 degrees short of meltdown. The radiation levels, though not immediately life-threatening, were dangerous, and the core cooked further as the contaminated water was contained and precautions were taken to protect the operators. Finally, at about 8 p.m., plant operators realized they needed to get water moving through the core again and restarted the pumps. The temperature began to drop, and pressure in the reactor was reduced. Two days later, however, on March 30, a bubble of highly flammable hydrogen gas was discovered within the reactor building. The bubble of gas was created two days before when exposed core materials reacted with super-heated steam. On March 28, some of this gas had exploded, releasing a small amount of radiation into the atmosphere. After the radiation leak was discovered on March 30, residents were advised to stay indoors. Slowly, the hydrogen was bled from the system as the reactor cooled.

In a This Day in History video, host Russ Mitchell takes us through the history of August 24th. On this day in 1814, British invaded Washington and set fire to the White House and the capitol building. On this day in 1989, Major League Baseball suspended Cincinnati Reds manager Pete Rose for life for gambling on baseball. On this day in 2006, Pluto got demoted; scientists claim that it is not a real planet, but a dwarf planet instead. Also on this day in 79 A.D., Mount Vesuvius erupted in southern Italy, devastating the prosperous Roman cities of Pompeii and Herculaneum.

What was the most televised broadcast in history? The answer to this question is quite surprising. The most televised broadcast in history occurred on December 24, 1968, when the Apollo 8 read from the Bible while orbiting the Earth for the first time. In addition, on December 24, 1979, Russia waged a nine year war against Afghanistan that would deplete their supplies and lead to the collapse of the Soviet Union. December 24 also marks the composition of one of the most famous Christmas songs of all time; Silent Night in 1818 by an Austrian composer. The last major event that occurred on December 24th, this time in 1923, was President Coolidge's lighting of the first public Christmas tree. To learn more, watch the This Day in History Video: December 24th.

In this clip from This Day In History, we go back to look at some things that have happened around us on the day of June 4th. From Oxford vs. Cambridge in a game of cricket, to the battle at Midway in 1942. See it all here in this amazing clip about June 4th.

In this "This Day in History" video clip learn about different events that have occurred on January 6. Some of these events include Joan of Ark being born and the first global flight for Pan-American Airways. Also, Nancy Kerrigan gets attacked and Morse develops the telegraph.