Final answer:
Benjamin Franklin left his printing job when he retired in 1748 and subsequently dedicated himself to public service and science, profoundly impacting American history through his various roles such as an inventor, statesman, and diplomat.
Step-by-step explanation:
When Franklin was 21, he departed from his job, embarking on pursuits that would profoundly shape American history and culture. However, the most significant turning point in his career occurred in 1748 when he retired from his prosperous printing business. Post-retirement, he dedicated himself to public service and scientific endeavors, showcasing his multifaceted talents as an inventor, writer, diplomat, and scientist.
Franklin's impact on American history is indelible. From his contributions during the French and Indian War to his role in drafting the Declaration of Independence, serving as U.S. Ambassador to France, and active participation in the Constitutional Convention, he stands as a pivotal figure. Embracing deism, his influence extended to philanthropy, evident in the founding of institutions like the University of Pennsylvania and Pennsylvania Hospital.