Answer: Historians label an event as a turning point when it marks the beginning of a distant historical period.
Step-by-step explanation:
A turning point marks the moment at which individuals, groups, nations or states move in a radically different direction.
The use of turning points is a historiographical short-hand for an event of paramount importance, a point where things change irremediably. So, a turning point constitutes a specific, significant moment when something begins to change.