First from 1885 - The act of uniting several persons into one fiction called a corporation, in order that they may be no longer responsible for their actions. A, B and C are a corporation.
A robs, B steals and C (it is necessary that there be one gentleman in the concern) cheats. It is a plundering, thieving, swindling corporation.
But A, B and C, who have jointly determined and severally executed every crime of the corporation, are blameless. - Ambrose Bierce, 1885 
From corpus, corpor- ‘body’