Final answer:
Literacy is considered one of the most impactful achievements of Mesopotamian early civilizations. It played a crucial role in various aspects of society, including the fields of mathematics, engineering, and astronomy. Literacy was closely tied to societal and economic prosperity.
Step-by-step explanation:
**Literacy** is considered one of the most impactful achievements of Mesopotamian early civilizations due to its significant contributions to various aspects of society. The development of writing allowed for the creation of written records, such as clay tablets and hieroglyphs, which provided valuable information about the advancements and contributions of these civilizations. Literacy also played a crucial role in the fields of mathematics, engineering, and astronomy, enabling the Mesopotamians to make important discoveries and inventions. Moreover, literacy was closely tied to societal and economic prosperity, as it facilitated commerce and technological progress.