Final answer:
A) The Great Depression. Hill based his original ABCX model on The Great Depression.
Step-by-step explanation:
The historical event that Hill based his original ABCX model on was The Great Depression.
The ABCX model is a conceptual framework used to analyze and understand the process of family adaptation to stressors and crises. Hill developed this model based on his observations and research on family functioning during the Great Depression.
During the Great Depression, families faced extreme economic hardship and had to adapt to the challenges of poverty, unemployment, and financial instability. Hill studied how families coped with these stressors and developed the ABCX model to explain the different factors that influence family adaptation and resilience.