Messenger and Advocate states that people can buy and free slaves provided they go to a different continent.
"The Abolitionists," Messenger and Advocate (April 1836): 295
If those who run through the free states, exciting their indignation against our brothers of the South, feel so much sympathy and kindness towards the blacks, were to go to the southern states, where the alleged evil exists, and warn those who are guilty of these enormous crimes, to repent and turn from their wickedness, or would purchase the slaves and then set them at liberty, we should have no objections to this provided they would place them upon some other continent than ours.