During a failed raid to free northern POWs in 1864, papers are found on the body of Union Colonel Ulric Dahlgren ordering the assassination of Confederate President Jefferson Davis. The discovery fuels outrage in the South and energizes the Confederate secret service. Now, historians have teamed up with descendants of the slain colonel to uncover who was behind the audacious murder plot and to consider if Abraham Lincoln's assassination one year later may have been a retaliatory measure.

The Spanish flu was one of the most devastating natural disasters in history, an unstoppable virus that swept the planet in 1918, killing tens of millions of people. New evidence suggests the possible birthplace was actually in America's heartland. Witness a globe-spanning story of death and denial on an epic scale, as we visit a mass gravesite, pore over old medical records and diaries, and use cutting edge scientific research to reveal the horrific truth behind this deadly pandemic.

On the morning of December 7, 1941, Japan's war machine attacked Pearl Harbor, killing over 2,300 American servicemen. The conventional story is that America was caught sleeping that day and was hit without warning. But newly declassified documents from U.S. Naval intelligence and the FBI reveal a very different tale, one of Japanese and German spies studying Pearl Harbor long before the assault with our agents watching them the whole time. So, how were we still caught so tragically off guard? Modern historians are determined to find out.

It's a Cold War story involving a turncoat KGB agent, doctored computer chips, and a fiery blast in the Siberian wilderness big enough to see from space. Modern historians investigate the claim of a June 1982 explosion of a Russian gas pipeline to see if it was the result of the world's first-ever cyber attack, a retaliatory measure secretly ordered by Ronald Reagan to bring the Soviet Union to its knees.

Casimir Pulaski was an American Revolutionary War hero who helped save George Washington's life in the Battle of Brandywine. He was known as the "Father of the American Cavalry," but new evidence suggests that the general may not have been male. Follow a team of anthropologists as they examine the bones found at Pulaski's monument in Savannah and run state-of-the-art DNA tests in order to determine if the officer was female or if someone else was buried in the tomb.

Benedict Arnold was a hero of the revolution. He was one of Washington's best generals. He had a new bride said to be the most beautiful woman in the colonies. And yet, just one month after marrying 18-year-old Peggy Shippen, Arnold reached out to the British and began to plot treason. What drove the celebrated general to betray his country? Investigators are now exposing a vast conspiracy to crush America's hopes for independence with Benedict Arnold's young wife at the center.

Most people think of Jamestown as the story of John Smith and Pocahontas, but new scientific research has revealed another prominent figure from America's first English colony. Discover the story of Sir George Yeardley, a commoner who became governor and went on to preside over the birth of the nation's democracy. Follow a team of archaeologists as they excavate the 1617 church where, according to English tradition, the leaders of the colony were buried, including our country's least known and first founding father.