In the Service's early days, the presidential vehicle wasn't exactly secure — the carriage was open, and horses can only gallop so fast.
The invention of the car was a huge step, but the desire to be close to their constituents kept presidents in danger
After President John F. Kennedy's death, the Secret Service gave itself a top-to-bottom policy overhaul, and open cars got the boot.
Today, the president's ride, to start, is completely sealed in case of a biochemical attack.
The fuel tank is sealed with foam, so it won't explode, even if it takes a direct hit.
The trunk carries an oxygen supply, fire-fighting equipment ...
And according to some reports, a supply of blood of the president's blood type.
In the front, The Beast has a night vision lens and tear gas cannons.
The agents have a Remington shotgun handy, just in case.
The run-flat tires are Kevlar-enforced, puncture- and shred-resistant ... but if they do get punctured, the steel wheels can keep rolling.
Of course, it's the steel, aluminum, titanium, and ceramic body that makes Caddy One a moving fortress.
The security layers are carefully installed, and several features overlap so there isn't a single weak spot.
The doors are as heavy as a 757 cabin door, with 8-inch thick armor plating.
The Secret Service won't discuss details about the windows, but Discovery spoke to International Armoring Corporation, which makes similar windows.
The first few glass layers can absorb a bullet, while the inner plastic layers essentially catch the bullet like a baseball glove.
This is what a window, with half the thickness, looks like from the outside after getting shot.
Mark Burton, the company's CEO, also demonstrated that JFK probably would have survived, had he had armored windows Nov. 22, 1963.
All the protection does come at a cost: Caddy One can only go about 60 mph, and only gets 8 mpg.
One asset that doesn't slow the car down is the staff of agents who go through intense training before getting behind the wheel.
And the counter snipers that line every route, to keep the agents on the ground from having to use all of Caddy One's features.
So the president can stay safe, even if he leaves the 'belly of The Beast.'
Here's a bonus slide to sum up everything.
That's how the president gets around on the ground
