This letter, folded to create its own mailing envelope, bears the word “Free” and the signature of Representative David Cobb. That pairing signals an early use of the “franking privilege,” which granted free postage for official business to Members of Congress. Congressman Cobb simply marked mail with an official signature and “free,” and posted it. The custom began in 1775 with the First Continental Congress. In this case, Cobb wrote to Elkanah Watson, a longtime supporter of canals and farming, to answer his questions about regulation of trade.