What does Thoreau mean by saying that the jailing of "one honest man" would bring the abolition of slavery in America?

The actual quote is closer to, one honest man can change the state by standing up to it... Thoreau felt that the individual wields much power in the face of adversity. An honest and respected man can oppose an insidious institution like slavery and other men will join him. When the people stand up to government, then government must yield to the people. One man can start a movement and wipe slavery away.