Congress took over Reconstruction from President Johnson after? A-Northern Republicans resigned from Congress.
B-former Confederate leaders were elected to Congress.
C-the president punished the South for the Civil War.
D-the president demanded an end to Reconstruction.

option a

explanation:

to cleberate the end of their war

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: