The assassination of President Abraham Lincoln by a failed actor named John Wilkes Booth is a tragedy ingrained in the minds of most Americans.

Now, the new book "The Lincoln Conspiracy: The Secret Plot to Kill America's 16th President — and Why It Failed" and the Fox Nation documentary "Secrets of Abraham Lincoln," is shedding new light on another, lesser-known tale of a plot to kill Lincoln, even before his presidency began.

"To be sworn in as the 16th president, Abraham Lincoln had to take a train from his home in Springfield, Illinois to Washington, D.C.," said Brad Meltzer, co-author of "The Lincoln Conspiracy" on "Fox and Friends" on Tuesday.

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"But the only way to get there was he had to go through Baltimore," he continued, "and Maryland at the time was a slave state. So the plot was simple. A secret society planned to kill Abraham Lincoln when he came through Baltimore and end his presidency before it even began."

However, with the help of America's first detective agency, Lincoln was able to elude his would-be assassins.

"In the middle of the night, there is a speeding train filled with passengers... and among them are two businessmen, there is a woman and she has a brother who is an invalid, but none of them are who they say they are," explained Meltzer.

"The man is actually Allan Pinkerton, the head of the famed Pinkerton detective agency. The woman is Kate Warne, the first female private [investigator] in all of America. And her so-called brother is not her brother at all, and he is certainly not an invalid — his name is Abraham Lincoln."

Josh Mensch, co-author of "The Lincoln Conspiracy," told Fox Nation that Pinkerton and his agency were the first to use law enforcement techniques that are commonplace today.

"He was ahead of his time in a lot of ways he and his agents would frequently wear disguises, assume false names and infiltrate criminal organizations and learn about them and then use that information to get them arrested or to prevent their schemes from ever taking place," said Mensch in the Fox Nation documentary.

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"They give Lincoln a code name, they give him a disguise," continued Meltzer on "Fox and Friends, "you won't believe the disguise they put him in — and that's how they saved his life."

To watch all of "Secret of Abraham Lincoln," go to Fox Nation and sign up today.

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