What important knowledge did william clark bring to the lewis and clark expedition?

The expedition was started from 1804 to 1806 which lasted over two years across the Louisiana Purchase to the Pacific Ocean and explore the lands of west Mississippi river. The expedition was confronted with harsh weather, starvation injuries, treacherous water, disease and even confronted hostile native Americans. however, this expedition helps to gain new knowledge about the ecology and unexplored geographical areas of America.

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