[SUSPENSEFUL MUSIC PLAYING]
NARRATOR: September 25th, 1780.
Urgent messages streamed toward a farmhouse just
south of West Point, New York.
The American Revolution rages into its fifth year.
But right now, General George Washington
and his senior aides, including Alexander Hamilton,
are in a state of shock.
Before them are captured documents
that reveal the most notorious act of treason
in American history--
a plot to sell out West Point in upstate
New York, America's most important Fort to the British.
Stunningly, the plot was hatched by West Point's
commander and the war's greatest hero, General Benedict Arnold.
In 1779, Benedict Arnold is a famed hero
of the American Revolution.
But a month after marrying 18-year-old Peggy Shippen,
Arnold begins to plot treason.
STEPHEN BRUMWELL: As Benedict Arnold becomes closer
and closer with the British, the whole question
arises of the extent to which Peggy was actually
involved, whether she was some kind
of Lady Macbeth-type figure.
NARRATOR: Arnold's handler in British intelligence
is John Andre, a man rumored to be Peggy's old flame.
a fact that opens the door to a controversial theory--
Peggy is behind the plot that's about to unfold.
The plan called for Arnold to lobby
for command of West Point.
Once in control, he would surrender the key American fort
to British troops.
Instead, Washington gives Arnold a more prestigious assignment--
a battle command in Washington's own army.
Peggy didn't take the news well.
CHARLENE BOYER LEWIS: Peggy Arnold
is informed that Benedict will not be receiving West Point,
but will be going back out in the field.
And this happens at a dinner.
She is shocked and stunned because that's not how
the plan was supposed to go.
NARRATOR: Some historians believe
Peggy's response betrays her knowledge of the plot.
Fatefully, Washington's offer falls through.
In August 1780, Arnold wins command of West Point.
The plot is on.
For Peggy Benedict and the revolution itself,
the stakes could not have been higher.
EDMUND EARLE: So this is our base
map for the Revolutionary War.
NARRATOR: To fathom the impact of losing West Point
to the American War effort, historian
Stephen Brumwell is working with graphic artist Edmund Earle.
In 1780, the British hold New York City.
The patriots control the territory to the north
in upstate New York.
West Point is a bulwark preventing a British breakout.
EDMUND EARLE: If Benedict Arnold had helped the British takeover
West Point, what would have happened
for the rest of the war?
NARRATOR: By taking West Point, the British
would split the colonies in two and cut
off critical supply lines feeding Washington's army.
STEPHEN BRUMWELL: You can see why this area was described
by strategists, most famously George Washington,
as the key to the continent.
If you could rupture that supply line,
you're going to have a dire impact on the survival
of the Continental Army, which is already on very short
rations in the summer of 1780.
NARRATOR: To Stephen, there is one
more diabolical aspect of this plot
that demands consideration.
STEPHEN BRUMWELL: It was not only about capturing West
Point, but there's very strong evidence
that the plot also envisaged the capture of George Washington.
NARRATOR: Stephen believes the plot is timed to go off
during a planned inspection of West Point by General George
Washington, ensnaring both the critical patriot fort
and potentially an even bigger prize with the capture
of America's greatest leader.
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