Presidential wheels (photos)

William Howard Taft was the first president to completely ditch carriages for cars with the purchase of his White Motor Co. Model M. The 40 horsepower seven-seater was the first Presidential State Car.

Warren Harding was the first president to take a car to his inauguration. His ride of choice was a Packard Twin Six.

Woodrow Wilson was one of the first presidents to ride in a Cadillac in 1918. Later, Calvin Coolidge was transported in a 1928 Cadillac Town Car.

Equipped with a full ammunition arsenal, two-way radios, and heavy-duty generators, a pair of 1938 Cadilacs christened the "Queen Mary" and "Queen Elizabeth" served Presidents Franklin D. Roosevelt, Harry Truman, and Dwight Eisenhower.

FDR's "Sunshine Special" Lincoln V12 featured a siren, two-way radio, extra-wide running boards, and grab handles for Secret Service agents. It was the first car built specifically for presidential use.

After the attack on Pearl Harbor, President Roosevelt made use of a heavily armored Cadillac that was originally owned by gangster Al Capone until the Sunshine Special could be modified with armor plating, bulletproof glass, and submachine gun storage.

The 1950 Lincoln Cosmopolitan was the vehicle of choice for President Harry Truman, who commissioned a pair in 1950. These vehicles would go on to serve Presidents Dwight D. Eisenhower, Lyndon B. Johnson, and John F. Kennedy.

However, the vehicle that is most closely associated with President Kennedy is the custom 1961 Lincoln Continental convertible, dubbed SS-100-X, in which he was assassinated.

After the assassination of Kennedy, we don't see too many more presidential convertibles. The SS-100-X underwent a number of modifications, getting a glass roof for President Johnson and ultimately a full metal roof with a small sunroof for President Richard Nixon to stand out of.

President Nixon ordered a 1972 Continental limousine. The vehicle featured armor plating, bulletproof glass, and a 7.5-liter V-8 engine. This was the same vehicle that President Ronald Reagan was entering in 1981 when an assassination attempt was made.

In 1983, Reagan received a Cadillac Fleetwood limousine. The tall greenhouse was wrapped, of course, in bulletproof glass.

When President William J. Clinton took office in 1993, he brought with him a custom Cadillac Fleetwood Brougham that was powered by a 7.4-liter V-8 from a Chevrolet heavy-duty pickup truck. The vehicle featured the standard armor and bulletproof glass, but it did not have a sunroof or running boards for increased safety.

In 2001, the Bush administration took delivery of an armored Cadillac DeVille.

During his next term, President George W. Bush ordered a 2005 Cadillac DTS custom. This vehicle featured all-wheel drive and is still used as an alternate presidential vehicle.

The 2009 Cadillac Presidential Limousine is the first State Car to not be based on a specific mass-produced model. President Barack Obama's method of conveyance features the chassis and power train of a GMC Topkick commercial truck and a variety of Cadillac styling and body components. Of course, there's about 5-inches of armor plating between the commander in chief and any would-be danger.