Because Ubaid, Sumer, Akkad, Assyria and Babylon civilizations all emerged around the Tigris-Euphrates, the theory that Mesopotamia is the cradle of civilization is widely accepted.
If you Google for washington monument height, the first listing you see is for a page about the monument at greatbuildings.com. Note that the page mentions that the monument has a base of 55 feet and a height of 555 feet, in keeping with what they call the standard Egyptian proportion of 10:1 height to base.
Pedestal. The stone base that holds all else up is 89 feet tall. This makes up an important, though often overlooked, piece of the overall height of the Statue of Liberty. Foundation. The next layer in the full height of the Stature of Liberty is the 65 five foot tall foundation.