briefly explain ONE specific historical event or development that accounts for the changes in united states energy sources between 1850 and 1900

There are different kinds of change. The one specific historical event or development that accounts for the changes in united states energy sources between 1850 and 1900 is that;

The creation of new technologies brought about a quick changes in U.S. industry between 1865 and 1900. It lead to the expansion of the scale of industrial production.”

New technologies changed U.S. industry such as the discovery of the oil  in Northern Pennsylvania, brought about the transition from a coal-based economy, to an oil-based economy.

Learn more about oil in Pennsylvania from

link

The event is the discovery of oil in Pennsylvania in 1859. This discovery was made in Tuntsville, Pennsylvania, by George Bissell and Edwin L. Drake, two American entrepreneurs.

This discovery led to an oil rush in Northern Pennsylvania, which quickly spread to the Appalachian basin. Finally, ample oil fields were found in Oklahoma and Texas, which helped the U.S. transition from a coal-based economy, to an oil-based economy.

monarchy doesn’t have to have the hereditary element. there have been elective monarchies in the past where you choose your king-for-life and when he dies elect someone else for the job.