Volunteering is so pervasive it's invisible. We take for granted all the things that have been pioneered by concerned, active volunteers.
Paul Revere earned his living as a silversmith. But what do we remember him for? His volunteer work. All activism is volunteering in that it's done above and beyond earning a living and deals with what people really care passionately about. Remember, no one gets paid to rebel. All revolutions start with volunteers.
Men have always volunteered, they just called themselves coaches, trustees, and firemen!