Creating a uniform system of time zones.
<span>The nation’s total wealth more than doubled between 1920 and 1929, and this economic growth swept many Americans into an affluent but unfamiliar “consumer society.” People from coast to coast bought the same goods listened to the same music, did the same dances and even used the same slang! Many Americans were uncomfortable with this new, urban, sometimes racy “mass culture”; in fact, for many–even most–people in the United States, the 1920s brought more conflict than celebration. Also a lot of people invested their money, went to jazz dances at night, theaters, bars, and mainly spent their money on new products</span>
Shopping have changed in that many products are cheaper than ever.
Over the last two decades there have bee high streets and local being as drastic as any in technology.over the years most of the shopping was done in traditional shops including local butchers,bakers,bakers e.t.c compared to today where supermarkets and other areas of shopping are opened longer hours
Not only establish control or presence, but to maintain control throughout their widespread nation through the use of these purposely similarly widespread system of military bases.
Answer:
It's the separation of powers.