Perhaps the most interesting group of Loyalists were enslaved African-Americans who chose to join the British. The British promised to liberate slaves who fled from their Patriot masters. This powerful incentive, and the opportunities opened by the chaos of war, led some 50,000 slaves (about 10 percent of the total slave population in the 1770s) to flee their Patriot masters. When the war ended, the British evacuated 20,000 formerly enslaved African Americans and resettled them as free people.
http://www.ushistory.org/us/13c.asp

Looks like Freedom came from the so-called tyrants!