A historian who has been an actor in the events which he narrates, has peculiar advantages and disadvantages. He can write with more minuteness of detail, and with a fresher and more life-like coloring. He can write with more confidence, and, drawing from his own experience and observation, is in this respect more trustworthy. On the other hand, he is more liable to be warped by prejudice, to see only the excellences and none of the defects of those with whom he has been identified, and only the defects and none of the excellences of those to whom he has been opposed, to be a partizan rather than a judge, and to make his narration little more than the reflection of his personal opinions or his personal sympathy and affection, hostility and spite.
The Church History of Isaac Backus has all the above-named excellences. To a large extent he was an eye-witness of that which he describes; and where not an eye-witness, he placed himself in closest possible connection with it by personal acquaintance with the actors, and by immediate and most diligent and thorough examination of records and other evidence. While it may be too much to say that he absolutely avoided the defects above named, yet his sound judgment, his natural candor and honesty and his elevated Christian principle, have made him as nearly free from them as perhaps any author who has written in similar circumstances.
–from the Editor’s Preface