President George W. Bush&39's Cadillac DTS still serves as an alternate State Car, despite the adoption of Cadillac One in this official role.

When you're the Commander-in-chief, the head of state, and generally the top dog of the United States of America, there will be times when you're expected to arrive to a variety of appointments, appearances, and meetings with other top dogs. But the President of the United States can't simply hop into his Ford Taurus and drive himself to meetings with foreign dignitaries--although, he may be tempted by the SHO. Rather, getting from point A to B when you're one of the most important people in the nation requires high levels of safety and reliability, as well as a touch of class. Enter the Presidential State Car: the official ground transportation method of the President of the United States.

Through the years, the various Presidential State Cars have shuttled the Commanders-in-Chiefs wherever a person of importance needed to arrive in style and safety. For example, President Warren Harding's, Packard Six was the first to shuttle a President to his inauguration and FDR's Sunshine Special was one of the first to be built to Presidential specifications. Other State Cars are famous for more ominous reasons, such as the code named SS-X-100 convertible in which President John F. Kennedy would meet his fate. There is, at times, overlap--being the property of the United States government, many State Cars served multiple administrations. Of course, as the years passed and safety and car tech advanced, so did the Presidential State Car--this advancement culminates in the current vehicle, nicknamed "Cadillac One," which is used to transport President Barack Obama.

We've gathered some of the most interesting vehicles, including an presidential ride that once belonged to a notorious gangster, into a gallery for your enjoyment.