In Revelation 17, the picture of the woman on the beast with seven heads. Heads represent kings, or, more correctly, kingdoms, countries, or nations. It also says there are seven mountains. A search of the scriptures finds that the mountains represent governments. The waters that are mentioned are peoples, multitudes, nations, and tongues. There are many guesses as to the seven kingdoms with great cities ruling them. Phoebes and Egypt, Assyria and Nineveh, Babylon, and Rome. We have some information to key off. Rev. 17 says they are also seven kings, five of whom have fallen; one is; the other has not yet come, and when he does come, he must remain only a little while. One is, so the one existing at that time was Rome, and Zechariah has the start of the woman’s existence at Babylon. Babylon was the first city to reach one million people. Babylon, the Medes and Persians, Greece, Antioch, Egypt, and Rome the Sixth As Rome changed into the Holy Roman Empire and into Europe, there became many large cities. The seventh head has to be away from Europe, and the only candidate for the seventh head is the USA. It must remain for a little while. A little while, or one lifetime, is 70 years.
There can be an argument put forwards that Assyria was the first because the land of Shinar includes Nineveh, and in Amos' description of Assyria, it was very similar to that of Babylon. Jonah's story of his trip to Nineveh and how, when he got there, they were repentant. There is a fundamental picture of the situation because Babylon was never repentant. That was the final key that needed to fall into place for full-blown wickedness to occur.