describe how the US came to build the Panama Canal and what it took. Why the completion of the canal was so important to World Trade​

whats the question? im not quite understanding your question.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

after defeating german forces in north africa allied leaders turned their attention to "italy," since this was the location that made the most geographic sense before invading northern europe via france.