Once,no humans lived on the continent of North America; then they began to journey,the first migrants arriving perhaps 15,000 to 20,000 years ago. When a skeleton from long-ago centuries is discovered,scientists want to study it for information about the person’s life and death,about her or his time and place in history.Sometimes artists are asked to reconstruct faces from the past using copies of their skulls.Then these nameless,unknown people can be "brought back to life"——remembered,and honored.Now,when their skeletons are discovered,their stories can be told.