Final answer:
John Brown was the person who tried to instigate a slave rebellion at Harpers Ferry, Virginia, in 1859, but his raid failed when the expected uprising did not take place and federal troops captured him.
Step-by-step explanation:
The individual who attempted to start a slave rebellion at Harpers Ferry, Virginia, in 1859 was the radical abolitionist John Brown. On October 16, 1859, Brown, along with a diverse group of eighteen men, including both Black and White individuals, led an attack on the federal arsenal at Harpers Ferry. Their plan was to seize the weapons and initiate a widespread uprising among enslaved people to abolish slavery. Unfortunately for Brown, the anticipated mass uprising of enslaved people did not materialize, and federal troops led by Colonel Robert E Lee intervened, resulting in Brown's capture. Brown was later executed. This brazen act underscored the rising tensions over slavery in the United States and foreshadowed the imminent Civil War.