Answer:
19th century into the early 20th century
Explanation:
The Second Industrial Revolution, also known as the Technological Revolution, was a phase of rapid industrialization from the late 19th century into the early 20th century. The First Industrial Revolution, which ended in the middle of 19th century, was punctuated by a slowdown in important inventions before the Second Industrial Revolution in 1870. Though a number of its characteristic events can be traced to earlier innovations in manufacturing, such as the establishment of a machine tool industry, the development of methods for manufacturing interchangeable parts and the invention of the Bessemer Process to produce steel, the Second Industrial Revolution is generally dated between 1870 and 1914
