Dr. Warren was raised in a Congregational home; some members of his family, including his son John Collins Warren, later became associated with the Anglican church. He was given to bouts of depression, perhaps as a result of his heart disease, to the extent that he lost the will to live to an old age. He was said to be generous and charitable. Personally Warren was of middle height and carried himself with a military bearing of a gentleman, but with an agreeable nature.