What technological changes at the turn of the 20th century affected american life ?

Telegraphs were common and provided newspapers with the latest news. Telephones were quickly becoming a feature in every household. 

Electric lights were replacing the much more dangerous gaslights at a fair clip. 

But the biggest improvements provided by technology were in mass production and railroad improvements. Mass production led to lower costs for manufacturers which were eventually passed along to consumers. Improvements to the speed and safety of railroads saved lives and provided fresh produce to much of the country. 

After the turn of the 20th century, you saw the wide-spread availability of autos, mechanized flight, radio and like.