What industries influenced economic development in the late 1800's?

The correct answer to this open question is the following.

The industries that influenced economic development in the late 1800s were oil, steel, and railroad companies.

That was a time when big businesses, new agriculture techniques, and larger manufacturing plants and industries changed the face of the American economy. The Transcontinental Railroad connected the East coast of the US with the West coast, and this represented a major improvement in the quality and cost of transportation.

the social contract theory

the us constitution is a living document, meaning that it can be changed over time as the country changes.