What was the significant social change and reform in the late 19th and early 20th centuries?

There were two technological innovations that profoundly changed daily life in the 19th century. They were both "motive powers": steam and electricity. According to some, the development and application of steam engines and electricity to various tasks such as transportation and the telegraph, affected human life by increasing and multiplying the mechanical power of human or animal strength or the power of simple tools.