Wikipedia's page at:http://en.wikipedia.org/wiki/Daylight_saving_time_in_the_United_States#Histo... states the following:

From 1945 to 1966 there was no federal law on daylight saving time, so localities could choose when it began and ended or drop it entirely. In 1954 only California and Nevada had statewide DST west of the Mississippi, and only a few cities between Nevada and St Louis. In the 1964 Official Railway Guide, 21 of the 48 states had no DST anywhere. I'm wondering if we have any additional details about the localities that adopted DST during this period and those that did not? Also, do we already incorporated data from the source mentioned? (the 1964 Official Railway Guide) Specifically, I was discussing this topic with another developer who was curious about Nashville, Tennessee. One could probably assume that it was on Central time - due to the Standard Time Act, but whether or not it used DST (specifically in 1949) or not is the question. The tz database entry for Chicago would say yes - but my guess is that it might not be certain that both Chicago and Nashville used DST that year. Thanks.