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.
washington monument dc part of national mall memorial parks national park service the washington monument dominates the united states capital skyline as a symbolic tribute to george washington s military leadership humble statesmanship and presidential fortitude and wisdomlans for a national monument began as early as 1783 when the congress passed a resolution to erect an equestrian statue to honor george washington construction started in 1848 and faced continuing construction challenges due to political turmoil and a lack of funds