The US Postal Service has played a key role in much of American history - from the Declaration of Independence to more recent mail-in voting. It was conceived of by the founders as the way to create a united, informed and effective American democracy. But today, the postal service s future is in danger. Winifred Gallagher spoke to NPR s Rund Abdelfatah about how the postal service created the United States and the case for investing in this pivotal institution.