One of the oldest and most distinguishable breeds, Siamese cats originated in Thailand, previously called Siam, in the 1400's and began appearing in Great Britain and the United States in the late 1800's.
The first registered Siamese cats in America were owned by Mrs. Robert Locke, pictured below with her cats "Calif," "Siam," and "Bangkok" circa 1899.
"History of Siamese Cats" by Diana Arnold
http://www.blackandtansiamese.com/historicsiamese/historic_before_1940s.htm
Physical Characteristics
Siamese have silky, cream-colored coats with darker "points" of color on their snout, ears, paws, lower legs and tails. Siamese kittens are born virtually white, but develop color points as they mature ... by the time a kitten is four weeks old, the points should show strongly enough that one can recognize which color they are.
The most common of the colorpoints is "Seal," brown points that may darken to almost appear black as the cat grows older. Other points include Chocolate Point (a lighter brown), Blue Point (silvery gray), and Lilac Point (a lighter, almost pinkish gray). More recently, breeders have experimented with outcrosses that result in Flame Point, (reddish color) Siamese, and also cats that have tabby style or tortoise-shell banding patterns in their points (Lynx Point and Tortie Point).
Purebred Siamese cats are available in both "Modern" and "Traditional" (a.k.a. "apple head") body types. The Modern Siamese has a wedge-shaped head, with large flared ears positioned so as to give a strong triangular appearance to the head; Body is long, lean and muscular. The Traditional Siamese cat is stockier overall, with a rounder face and less angular body type. http://www.petfinder.com/cat-breeds/Siamese
Behavior
Highly intelligent and loyal, Siamese cats are very active and curious animals that remain playful well into adulthood.
Siamese cats are very social, and crave active involvement in the lives of their owners. They thrive best in environments where they will receive lots of affection and attention, and they will pine if left alone for too long. They tend to be talkative, and speak with a distinctively raspy meow.
From the CFA Siamese Cat Breed Profile, by Betty White:
"Whether it is by vocalizing or by body language, the Siamese is determined to communicate. The degree to which they are talkative depends a good deal on the amount of conversation that is directed their way. In addition, they tend to be vocal in direct proportion to the desired end, always demanding the last word!
"Siamese do not tolerate isolation (or being ignored) well; they want to be a part of their owners’ lives, as they hold firmly to the belief that they are man’s best friend. (They play fetch exceedingly well, and have the distinct virtue of returning the thrown object to your lap instead of your feet!) They are in one’s lap, on one’s newspaper, in one’s bed, and completely in one’s heart. There is no better companion cat than "The Royal Cat of Siam."
http://www.cfa.org/breeds/profiles/articles/siamese.html