One of the great early American examples of a lawyer ensuring that unpopular defendants got a fair trial, even defendants with whom the lawyer may have disagreed took place in Boston in 1770. The lawyer was John Adams and the defendants were the British soldiers who were accused of murder from their involvement in the Boston Massacre of March 5, 1770.
The Law Library of Congress has posted copies of three published accounts of the records and transcripts of the trial, a history of the Massacre and trial, and a character sketch of Adams that includes his Speech on the Boston Massacre.
Great reading on one of the great ethical responses of the revolutionary bar!!