Probably that none of the delegates from the thirteen colonies who signed the Declaration of Independence in 1776 in Philadelphia, in statehouse of Pennsylvania (now known as Independence Hall), ever dreamed that the newly formed state will reach in less than two centuries one of the world's superpowers. After all it was about 1.5 million colonists (one fifth of then England's population), in overwhelming majority farmers, occupying, that's right, 2,150,000 square km (an area about 16 times the one of England).
Then why was the mentioned building included among the UNESCO World Heritage Sites, if not for that the United States is a superpower (in fact this wouldn't have been a viable argument)? Because "the universal principles of the right to revolution and self-government as expressed in the U.S. Declaration of Independence (1776) and Constitution (1787), which were debated, adopted, and signed in Independence Hall, have profoundly influenced lawmakers and politicians around the world." I would add "for a while", or at least "at declamatory level."
Independence Hall was designed by Edmund Woolley and Andrew Hamilton in the Georgian style, and built by Woolley between 1732 and 1753. It's a red brick building, and consists of a central building with belltower and steeple, attached to two smaller wings via arcaded hyphens. The wings were demolished in 1811-1812, but have been reconstructed subsequent. In 1753 Thomas Stretch erected a giant clock at the building's west end, which was also removed about 1830, and restored in 1973. The building was initially inhabited by the colonial government of Pennsylvania as its State House, from 1732 to 1799.
About the stamp, a Global Forever First-Class Mail International one (1.10 USD), I wrote here.
Independence Hall - WIkipedia
Sender: Irma Brown (direct swap)
Sent from Bath (Pennsylvania / United States), on 08.04.2013
Photo: Lisa Andres