Three major changes that happened near the turn of the century were that people were able to employ themselves in different factories which were having increasingly better conditions (due to union workers promoting rights), there was a better access to healthcare than in previous decades and finally, school was becoming more and more widespread and pupils were obliged to go.
All of this led to positive changes in terms of living quality for people as they were able to live a better life.
I hope you meant from the 19th to the 20th century?