What were the consequences of the Fugitive Slave Act for slaveholders, white northerners, free African Americans, and fugitive slaves?

One of the major consequences of the Fugitive Slave Act is that all of the slaves that had escaped and have gone fleeing north or are trying to find shelter, had to be returned to the South or they could face federal charges for harboring a fugitive. White northerners, even if they were against slavery, were forced to do thi as well. For already free African Americans, this means someone from the south could easily come and capture you in the north and make you become a slave if you did not have your proof of freedom papers on you, even then they would most likely just tear them up or get rid of them in some way shape or form.