Final answer:
The election of Abraham Lincoln as president led directly to the secession of Southern states.
Step-by-step explanation:
The event that led directly to the secession of Southern states was the election of Abraham Lincoln as president. This event took place in 1860 and was a major factor in the secession of the Southern states. Lincoln's election alarmed many Southerners who believed that he would work to limit or abolish slavery.
Learn more about Causes of the secession of Southern states