Alphabets have been around in some form for at least four millennia! Think of Egyptian hieroglyphics, for example. No one knows for sure what the first alphabet was. About 1500 BC, some Eastern Mediterranian Semites invented the alphabet from which ours is probably descended. It was made up of consonants. Later, the ancient Greeks adapted the Semitic alphabet for their own use, and they added vowels. The alphabet we use today, called Modern Roman, evolved from these.
Answer provided by Dr. Universe