Which accurately describes a chart developed 20 years after a historical event?Which accurately describes a letter written during the time a historical event occurred?

this is a very vague question

Explanation:

historians actually date events after about 50 years

herodotus taught this. herodotus was an ancient greek historian who was born in halicarnassus in the persian empire. he is known for having written the book the histories, a detailed record of his "inquiry" on the origins of the greco-persian wars.