One of the biggest factors of change in the 1800s was the invention of the cotton gin. So suddenly the southern states in America went from slavery dying out to just about a full revival. It just wasn't profitable.  The southern States had slaves working the cotton fields, and British cotton was cheaper. During this time the importation of slaves became illegal, making a slave a high priced good. The price of a slave increased exponentially during this time.  Slaves were expensive and plantation owners had no money.  The Cotton Gin changed that. Cotton was processed faster, cheaper, and easier than ever before.

                Another new "invention" was the idea of interchangeable parts.  This idea made it easier to create universal goods instead of handmade items.  Production could become faster and cheaper than specialist shops had ever done before.

The Cotton Gin, Interchangeable parts... The North was already the manufacturing side of the States. Now they were giants.

                America split in half because of this.  The major industry in the north and the farming agriculture center in the south spit the nation.  Both sides wanted things and the other side denied its rights.  Both would argue and fester resentment.  The nation was split for good.