William Howard Taft
Taft was not only the fattest President of the United States; in 1909 he became the first one to ride in an official presidential limousine. In fact there were four official presidential limos: a White Steamer, a Baker
Electric, and two Pierce-Arrows. From this selection, it's obvious that Taft was an early proponent of no-fossil fuel vehicles.
William McKinley
In 1899, McKinley was actually the first president to take a ride in a car, a steam-powered Locomobile.
Warren Harding
Harding was the first president who knew how to drive a car before taking office. He was also the first president to ride to his inauguration in a limo.
Calvin Coolidge
Typical of Calvin Coolidge's reputed stingy demeanor, he rented his presidential limousines to save money.
Franklin D. Roosevelt
Roosevelt's official presidential limo was a Ford equipped with hand controls because he enjoyed driving despite his polio affliction. He only stopped driving himself after experiencing a 1933 assassination attempt in Chicago. From then on, his limousines were armor-plated.
An additional note: on December 8, 1941, one day after the Japanese attack on Pearl Harbor, Roosevelt rode to Congress to deliver his declaration of war in gangster Al Capone's armor-plated limo. The car was then owned by the Department of Treasury following Capone's tax evasion conviction.
Dwight D. Eisenhower
Eisenhower was the first president to have a Plexiglass bubble installed on the roof of his limousine in order to be seen by crowds even in bad weather.
John F. Kennedy
A sign of his times, JFK's Lincoln Continental was tricked-out and gadget-laden much like a James Bond vehicle. It had removable roof panels that could be configured in various ways, and the back seat could be raised more than 10 inches. The car also came with a two-way radio and a telephone.
It was leased to the White House for a mere $500.
Lyndon Johnson
After Kennedy's assassination, Lyndon Johnson had the presidential Lincoln overhauled, adding 1600 pounds of steel plating and bullet-proof glass, and a non-removable top.
Ronald Reagan
Preserved in the Henry Ford Museum in Dearborn, Michigan, Reagan's Lincoln is the car he took refuge in after John Hinckley's assassination attempt. Earlier, it was Gerald Ford's limo when an assassination attempt was made on his life while he was riding in it.
This Lincoln is the last presidential limousine to be preserved. All subsequent presidential vehicles are now destroyed by the Secret Service for security reasons.