The reference is to inhabitants of the town of Jericho, located some 20 kilometres southeast of Jerusalem near the banks of the Jordan River. That a contingent would donate their time and make the journey to Jerusalem to assist in the repair of the wall beside the priests (and hence close to the temple) speaks to their zeal for the Lord and their loathing for the derision Israel had suffered (Nehemiah 2:17). Groups from other villages and towns are mentioned throughout the chapter.
2 And next to him the men of Jericho built. And next to them Zaccur the son of Imri built.