what made anne frank's diary a piece of historical record ? why was it considered authetic ?

Anne's diary is a daily record of a young girl coming of age while hiding from the Nazis. The diary not only documents actual historical events but details thoughts and feelings of real people forced into hiding. We get a document that describes not only the Jewish point of view but rather a human point of view. Within the text we see a girl growing up with all the insecurities, hopes, and dreams of any adolescent girl. Yes, the diary was found intact with Anne's distinct writing and voice.