Asource that is written or created by a person who experienced and event personally is called a

The answer is: Primary source

Primary source could only created from the recollection or the historical proof that is made by the people who are involved in the event.

Examples of primary sources are: Letters that given to a certain person during the historical event, the diary of a person that involved in the historical events, agreement signed by the organizations that involved in the historical event, etc.

to keep us neatruel and not get involved in any wars

he assumed control of treaty negotiations with a hostile power