Energy.
The Second Industrial Revolution<span>, also known as the </span>Technological Revolution,<span>was a phase of rapid industrialization in the final third of the 19th century and the beginning of the 20th. The First </span>Industrial Revolution<span>, which ended in the early-mid 1800s, was punctuated by a slowdown in macroinventions before the Second Industrial Revolution in 1870.</span>
They are using the Scientific Method, Chronological Method, Research Method, and the Historical Method
The underlined digit is 2 hundreth thousand
The Kansas Nebraska Act made it so that the two states could decide whether they wanted slavery or not