How did the Ganges River impact ancient India?
It was highly significant, especially when coupled with the Rig Veda's hynms & discussions of the Great River of Wisdom, The 7 branched Saraswati. Coupled with the data from the Landsaat satalittes, one can in fact find this river system. It has changed its direction at least 6 times, once incorporating the Ganges within it. Most of the hymns of the Rig Veda (the oldest book in the world) refer to a large sea to sea maritime culture spanning what is now Northern India & Pakistan - & probably bits of Afghanistan & Tibet as well. Much of Hinduism is anchored in the presence of great bodies of water . (D Frawley, 1991. Gods, Sages, & Kings: Vedic Secrets of Ancient Civilization.)