Generally speaking, infrastructure means "<span>A. the fundamental facilities and systems that serve an area," although if you're referring strictly to construction, then it would be the beams, foundation, etc. </span>
The main advantage which the Germanic tribes had in their conflict against the Roman Empire at the time during the 3rdr and 5th century was that they were very motivated to defend their own lands which were invaded by the Romans. They also knew the terrain and felt comfortable being there.
It frees black slaves in the South. "All persons held as slaves within the rebrllious states are and hencefowars shall be free." It dosent however free existing slaves in the north, that happens 2 years later. In December 1865 the thirteenth amendment was ratified finally ending slavery in the United States.