Limousine, as you can probably tell by the spelling, is a French word (anglicized by adding an 'e'), a one-time province in the central region of France. Shepherds in Limousin in the distant past developed a large hooded cloak as protection from that region’s rainy weather. As sedan chairs, and later large horse drawn coaches became fashionable in France the sedan bearers or drivers were often exposed to the weather while their passengers where sheltered in an enclosed compartment. To protect themselves from the weather the chauffeurs adopted the Limousin cloak which was the most effective garment they knew of to protect them from the weather. Thus the chauffeurs now looked like Limousines (i.e. people from Limousin).

Somehow, probably by observers saying “here comes a Limousin“, or something similar, as these vehicles and their hooded drivers approached, the name came to apply to luxurious professionally driven passenger transportation. The popularization of this word proceeded from the early 1700s up until the present day, and it became not only a French, but an international usage. During this period motorized transport was invented, but many of the early automobiles retained an open drivers seat, and some drivers continued to wear the Limousin cloak. Eventually the original meaning was largely forgotten, and the word limosine took on its modern meaning. The Model T was the car for every man, but the limousine was something special.

In America in the big band era, Benny Goodman and other big band leaders needed large vehicles to transport their bands and instruments, so they adopted long stretch linousines. From here the limousine came to be a more and more familiar sight on the American roads, and to be associated with celebrity, status, or wealth. The cars known as limousines stretched longer and lower up through the 1970s. American presidents acquired armored limousines along with increased powers and new respect for the “executive order.“ Today, with the popularity of sports utility vehicles, tall stretch limousines made from extended SUVs are becoming the “height” of style.

Read more at Suite101: From Limousin to Limos: The word Limousine comes from a province in France http://transportationhistory.suite101.com/article.cfm/from_limousine_to_limos#ixzz0b2xRx5LU