The use of "poll taxes" as a means of racial discrimination was most effectively stopped by which of these methods? a) executive order b) congressional law c) supreme court ruling d) constitutional amendment

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:

it proved indian land claims were unjustified.