After Alec died, he turned the guillotine into a few bugs and searched the house to see what the slaves did.
Each slave reacted differently. Some were rocking on the floor, crying softly, others marveled at having the freedom to act as they pleased. Some of Alec's now former subordinates saw the slaves acting oddly and started rushing to where Alec was. They found his headless body slumped over his desk, still spurting blood onto the floor around it.
That was the last thing any of them ever saw.
After Salem had 'removed' every single possible threat in the mansion, he entered and began directing people to one single meeting point. Every person he found made him regret not torturing Alec a little more.
'What's done is done, I guess.' he thought, as he helped the last person reach the meeting point.
"Where are we going?" One of the people asked.
Salem ignored them since he couldn't reply in an effecient manner.
"Wait. Stop. Where are we going?" The same person tried to appeal to the crowd. "How can we be sure that where he's going isn't worse than where we just were?"
A few members of the crowd voiced their dissent. "If he were going to torture us or enslave us, couldn't he have done it here?" They pointedly left out the fact that he could have a project somewhere else.
As they left, he sent a few bugs to the wine cellar and had them explode.
Fire had become sort of a symbol for Salem. Rather than have an aversion to it, he felt drawn to it. He felt he had been born from fire.
When they reached the clearing, Salem climbed a tree. Looking towards the town, he saw a massive pillar of smoke that he felt represented his success.
Climbing down, he led them to Alina and Ruby to let them sort out the addition of about 50 people.
The newcomers fit right in with the crowds. When the town had been created, it became a beacon of hope for its residents. Now it became a site of merriment and joy. Families that had been split by slavery, long-lost friends, and old neighbors now reunited in one town. This town was a fresh start for all of them. A place to start from scratch. No longer did they fear Salem. Now they christened him a hero.