Harappan civilisation

Harappan civilization is the first civilization of India found near the Indus valley. Evedences of Harappan civilization was first found by the team of Cunningham,he was the first director-general of ASI. He was confused by seeing these evedences and tried to add them rigved period (After Harappan civilization/many years later this period started). Because of his confusion, everyone thought that rigveda period or Indian history first started from ganga valley (because riveda period started from ganga valley). After many years,in1924,John Marshall, Director-General of ASI announced this is new civilization or very old civilization of India to the world. Because of John Marshall,we know India's first civilization start from Indus Valley not from Ganga valley.