4. What caused the first real threat of secession? __ Federal tariffs __ Abolitionism __ Import bans D The Ema ncipation Proclamation

The first real threat of secession was caused by Federal tariffs. The Nullification Crisis in the early 1830s, particularly involving South Carolina, was primarily driven by opposition to federal tariffs, which were seen as unfairly benefiting Northern industries at the expense of Southern economies.