What were the reasons for the rapid economic development of the United States after the end of the Civil War?

Reasons for the rapid growth of the economy:

A wealth of natural resources, combined with the industrial base of the northern states already established by 1865.
American version of the development of agriculture.
A constant influx of hardworking people from Europe, and then from China.
The development of new states in the west after the civil war, railways and highways were built there.
Processes of centralization of production and concentration of capital.

As a result, by 1894 the country came out on top in the world in terms of industrial production.