The Corpus Juris Civilis, the founding document for many European law codes, is most closely associated with the Magna Carta, which came far before it.
Yes! Trains started to be built in 1839 to connect the royal palace of Naples to the seaside. More were built in 1861 to connect from the Alps to Sicily.
It is called impressment. The British would capture American ships and force them to work for the British.
Government intervention and Disequilibrium
The Americans got involved in the Vietnam War because they did not want another Communist party to hold Vietnam as its captive. Vietnam along with other South East Asian countries have undergone communist rule from China and France, Americans did not want to see that happening again, that's why they aided or supported the Vietnamese from the war that they were waging against communist countries.