Final answer:
The Fugitive Slave Act is the act that made more people in the North advocate for the abolition of slavery and ultimately harmed the South more by exacerbating tensions between the two regions.
Step-by-step explanation:
The passage of the Fugitive Slave Act significantly heightened tensions between the North and South, leading more people in the North to advocate for the abolition of slavery. It mandated harsh penalties for those who assisted escaped slaves and compelled Northerners to participate in the recapture of fugitives, an involvement that was against their will and beliefs. This federal law reinforced for many the notion of a "Slave Power," a concept where a minority of slaveholders maintained disproportionate control over the federal government. The Fugitive Slave Act was seen as a violation of individual rights and state sovereignty since it imposed the will of slaveholders onto free states. Despite the South's frequent defense of states' rights, they utilized federal power to strengthen and safeguard the institution of slavery