There were three Nebuchadnezzar's who reigned. Assuming that you are talking about Nebuchadnezzar I, he reigned during 1125 - 1104 BC.
The following are correct:
A moat filled with water from the Euphrates River surrounded the city.
Walls around the city provided protection from enemies.
They both talk about the freedom of black people and the emancipation proclamation falls under the freedom of black people
