The 1850 Fugitive Slave Law caused outrage in the Northern States. It caused thousands of Northerners to be convinced slavery should not be allowed in the western territories. Eight states in the North passed "personal liberty" laws. These prevented any official from helping to return a runaway slave. Southerners regarded these laws as being illegal attempts to prevent the return of their slaves. In the North, free black communities provided runaway slaves with sanctuary and hid them from the hired kidnappers searching for them. About 15,000 free blacks emigrated to Canada, the Caribbean and Africa after the 1850 law was passed. Thousands of others including free blacks were not so lucky and were sent South.