Did Nehemiah rebuild the whole wall of Jerusalem or only parts of it?

Answer:

When the Babylonians destroyed Jerusalem, the Bible noted the following, "And all the army of the Chaldeans who were with the captain of the guard broke down the walls of Jerusalem all around" (II Kings 25:10; also Jeremiah 52:14).

Seventy years later, Nehemiah heard of the destruction and wanted to repair the walls. "And they said to me, "The survivors who are left from the captivity in the province are there in great distress and reproach. The wall of Jerusalem is also broken down, and its gates are burned with fire."" (Nehemiah 1:3). Nehemiah arrived and inspected the walls. "Then I arose in the night, I and a few men with me; I told no one what my God had put in my heart to do at Jerusalem; nor was there any animal with me, except the one on which I rode. And I went out by night through the Valley Gate to the Serpent Well and the Refuse Gate and viewed the walls of Jerusalem which were broken down and its gates which were burned with fire. Then I went on to the Fountain Gate and to the King's Pool, but there was no room for the animal under me to pass. So I went up in the night by the valley, and viewed the wall; then I turned back and entered by the Valley Gate, and so returned" (Nehemiah 2:12-15).

Jerusalem has multiple gates, but notice that while some gates were blocked by collapsed walls, others were open, implying that portions of the walls still stood. It is more clearly seen in Nehemiah 4:6-7, "So we built the wall, and the entire wall was joined together up to half its height, for the people had a mind to work. Now it happened, when Sanballat, Tobiah, the Arabs, the Ammonites, and the Ashdodites heard that the walls of Jerusalem were being restored and the gaps were beginning to be closed, that they became very angry." As you read through Nehemiah 3, you see the number of workmen on each section being rebuilt varied. Thus we can assume that some sections were heavily destroyed and others only partly. The work joined the various remaining sections back into a whole wall.