Postal inspectors began their work when Postmaster General Benjamin Franklin named William Goddard surveyor of the post in 1776. Through the nineteenth century, their roles evolved beyond their primary duty to ensure the successful transportation of mail. By the mid 1800s, inspectors were playing an active role in criminal investigations and law enforcement.
As mail volume grew, so did the number of unscrupulous individuals who tried to steal the mail or use it for illegal or harmful purposes. When swindlers used the growing mail system to target people after the Civil War, inspectors added mail fraud investigations to their duties.