5. what famous invention of the gilded age threatened the oil industry and transformed american society?

The Railroads

Railroads completely transformed the United States socially, politically, and economically during the Gilded Age. Literally the engine of the new industrialized economy, they facilitated the speedy transportation of raw materials and finished goods from coast to coast. In addition to raw materials, these “iron horses” carried people west to settle the heartland and the frontier. As the railroads grew in power, they exerted increasing influence on local and state governments, eventually prompting Congress and reform-minded presidents to pass laws to regulate the new industry.

the enslaved people onboard suffered from illness with some frequency

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.