Answer: Mesopotamia and Indus Valley Civilization were contemporary civilizations and there is evidences of the trade between them between 2600 and 1900 BC. The Harappa civilization was larger than Mesopotamia. Burnt bricks were more commonly used in Harappa than Mesopotamia. The Indus people were less concerned with religion and more concerned with commerce. The Indus people are known for their drainage systems, town planning and cleanliness. Both civilization had writing but Mesopotamians had better math and better calendars. In Mesopotamia there is a evidence of war with other lands. The Indus people remained mostly at peace and were not expansionist.