Abstract
That the preponderance of the evidence should determine civil cases has long been taken for granted, but not for as long as most assume. It turns out that the preponderance of the evidence standard for resolving factual disputes did not arise until the late eighteenth century. Rather than being a precursor from which the requirement of proof beyond a reasonable doubt in criminal cases diverged, the preponderance standard was born with or a little after the reasonable doubt rule as its contrasting twin. Even after the standard emerged, not until the mid-nineteenth century did American judges find it necessary to tell civil juries that for the party bearing the burden of persuasion to prevail, that party must show that the preponderance of the evidence supports its contentions. In England, such jury instructions did not appear until still later. Even today, courts formulate the standard in different ways, leading to different results. Scholars have not previously explored any of this history, leaving a gap which contrasts strikingly with the distinguished scholarship devoted to the origins of the reasonable doubt rule. A number of previously unavailable trial transcripts and descriptions can now contribute to a fuller picture of the origins of the preponderance standard. This Article seeks to trace and explain how lawyers, judges, and scholars created and developed that standard.