There is no such thing as the Mesopotamian alphabet; instead, the Mesopotamians used around 400 to 1,000 symbols to write with. At first, they used symbols representing different trading goods. These symbols evolved over time, and more were added until the writing system, called cuneiform, became a complete writing system.
Cuneiform is the earliest known writing system. It is believed to have been developed between 8,000 and 4,000 B.C. in southern Mesopotamia. Its symbols were originally made into tokens out of clay, but later, the symbols were inscribed in clay, normally using a triangular stylus.
As the language developed, the Mesopotamians began to use symbols to represent sounds. Then they developed systems to help people pronounce words and put them into the proper context.