Final answer:
The Fugitive Slave Act of 1850 was objectionable to Northerners for reasons such as enforcing citizen participation in slave-catching, denying jury trials for accused runaways, and extending slave catching into free states, but it did not abolish slavery.
Step-by-step explanation:
Northerners objected to the Fugitive Slave Act of 1850 for several reasons, but one reason that they did not object to is it abolished slavery in the United States. The act actually did the opposite by enforcing stricter measures to ensure the return of escaped slaves to their owners. The Fugitive Slave Act included provisions such as requiring citizens to assist in the capture of escaped slaves, denying fugitive slaves the right to a trial by jury, and allowing slave catchers to operate in free states. These measures provoked outrage in the North as they compromised the civil liberties and sovereignty of northern states and their citizens, while also expanding federal power to protect the institution of slavery.