Respuesta :
Answer:
America's railroads began using a standard time system involving four time zones, Eastern, Central, Mountain and Pacific
Explanation:
I used the the History Channel website and I got the question right on a test
					                   On November 18, 1883, America's railroads began using a standard time system involving four time zones, Eastern, Central, Mountain and Pacific. 
					                
					                
					              
					                  