I believe that historians have found artifacts that the Indus Valley Civilization made in the area the Sumerians were. There also might have been written evidence.
Https://en.wikibooks.org/wiki/US_History/Print_version
They dident know how to survive because they dident know how to use their resources so they lived a harsh life but they moved to Jamestown to hide and they soon got help and realized how to use their resources <span />
One of the reasons why the Battle of Gettysburg was a turning point in the Civil War is because "<span>The battle weakened Lee and stopped his invasion," although it also led both sides to reevaluate their positions. </span>
