Final answer:
Northern states passed personal liberty laws to counteract the Fugitive Slave Act of 1850 and protect free African Americans and escaped slaves from being forcibly returned to slavery.
Step-by-step explanation:
To resist being made complicit in the slave system, northern states passed personal liberty laws that banned the forcible return of slaves to the South. These laws were in response to the more stringent Fugitive Slave Act of 1850, part of the Compromise of 1850, which heightened the North-South tensions by compelling officials in free states to assist in the recapture of runaway slaves and by making it possible for free blacks of the North to be forced into slavery due to the difficulty in proving their free status. Furthermore, personal liberty laws were a significant effort to undermine the Fugitive Slave Act and protect African Americans from being forcibly returned to slavery