How were US time zones established? Why aren’t all counties in IN, KY, and MI on central time?

by thisismy1stalt

The border between ET and CT is wonky and seemingly arbitrary. TBH I don’t even understand why Ohio is on ET. The borders make a bit more sense out west where there are fewer people per square mile, but in the east major metropolitan areas straddle the border. An hour outside of Chicago is ET. Same for Louisville.

CptNoble

The FAQ has a section on time zones.