Active loyalists comprised probably 1/5 of the American population
during the Revolution. They were a diverse lot who tended to either have
strong ties to England and the Crown (Anglican ministers, for instance, or
British appointed officials like Hutchinson), or some sort of long-established
animosity toward the colonial leadership (in the south, back-country Scots
tended to remain loyal because they hated the seaboard "establishment").
During the war, many loyalists stayed close to the British army. A great many
clung to New York because the British held that city for much of the war.
Perhaps as many 100,000 loyalists left the country after the revolution, many
winding up in Canada.
See also: Thomas Hutchinson