What was one key event from the 1850s that escalated tensions between the North and South? How did the push for western expansion impact this event?

One event
from the 1850s that heightened tensions between the North and the South was the raid by the
abolitionist John Brown on the federal armory at Harpers Ferry, which was then in the state of
Virginia.  This raid helped increase tensions because the North and South reacted to it in
different ways.

In this raid, Brown and his followers took control of the
federal armory.  Their plan, such was it was, was to give out weapons to the slaves who, they
were sure, would flock to them.  These slaves would then carry out an armed rebellion.  Brown
and his people were defeated and Brown was later executed. 

The argument
on the part of...

href="https://www.ushistory.org/us/32c.asp">https://www.ushistory.org/us/32c.asp