THE FIRST GREAT TRAIN ROBBERY
On the show: A gang of thugs halt a steam train in its tracks and ruthlessly rob the passengers. They're no ordinary criminals though - they're politically motivated Southern rebels who want revenge on the North for beating them in the US Civil War. All of which amounts to a juicy case for the Pinkertons, particularly as no train robbery like this has ever happened before.
In reality: The Pinkerton National Detective Agency really did crack down on America's first ever train robbers: the Reno gang. But these outlaws weren't interested in politics and the Civil War. They were just out for the money. After a spate of crimes, the Reno gang members were apprehended by Pinkerton agents and handed over to the authorities, only to be eventually nabbed and executed by vigilante lynch mobs.
THE SECRET SOUTHERN BELLE
On the show: Pinkerton detective Kate Warne often goes undercover to mingle with criminals, at one point pretending to be a Southern belle looking to encourage a new uprising against the North.
In reality: "Graceful in her movements" but with eyes "filled with fire" - that's how the real Allan Pinkerton described the real Kate Warne after he recruited her as America's first female detective. And, like the version we see in the TV show, Kate Warne was a skilled undercover operative. Able to take on new personas at the drop of a hat, she once posed as a fortune teller to coax out someone's secrets. She also did indeed pretend to be a wealthy Southern belle to mingle with Southern rebels and uncover plots against the nation.
THE CRIMINAL DATABASE
On the show: Agency chief Allan Pinkerton keeps extensive records of known and suspected criminals which Will and Kate sometimes use in their investigations.
In reality: It's all true. As well as boasting energetic field operatives, the Pinkerton National Detective Agency kept an extensive collection of wanted posters, newspaper clippings and mug shots which formed the world's first criminal database. It was just one of the many practices that would be copied by US police forces and the FBI.
THE PLOT TO KILL LINCOLN
On the show: Kate Warne reveals she helped save Abraham Lincoln's life just before he became US president. Under threat from Southern extremists, Lincoln posed as Kate's invalid brother as she smuggled him to safety on a passenger train.
In reality: Incredible as it sounds, it's a true story. Allan Pinkerton was a devoted friend to Lincoln, and - as the nation bristled for Civil War - he deployed Kate Warne to go undercover and find out if there was a threat to the president-elect's life. After realizing there was an apparent plot to murder him as he travelled through Baltimore on the way to Washington DC, Kate did indeed accompany a disguised Lincoln on an extremely tense train journey through the danger zone. It's thought the famous Pinkerton motto, "We never sleep", was inspired by Kate tirelessly keeping watch over Lincoln during the trip.
THE CARETAKER TURNED AGENT
On the show: When Kate Warne moves into her rustic home in Kansas City, she's met by caretaker John Bell, who's as good with a shotgun as he is with a saw and hammer. A brave outsider who pushes aside any casual bigotry he gets as a black man, Bell soon starts playing a part in Pinkerton cases.
In reality: It's pretty clear that the character of John Bell was inspired by a real African-American named John Scobell. A former slave from Mississippi, Scobell was recruited as a spy by Allan Pinkerton, and was sent on dangerous missions to gather information from the South during the Civil War. He would pose as a cool, labourer and even a servant to other Pinkerton agents, and was described as a "cool-headed, vigilant detective" by Allan Pinkerton himself.
Watch The Pinkertons Sundays at 8pm on Drama.