Here's the 30-second version of the rich history of the alphabet.
The original set of 30 signs, known as the Semitic alphabet, was used in ancient Phoenicia beginning around 1600 B.C. Most scholars believe that this alphabet, which consisted of signs for consonants only, is the ultimate ancestor of virtually all later alphabets. (The one significant exception appears to be Korea's han-gul script, created in the 15th century.)