How did agriculture change from 1850- 1890?

The book by john kenneth galbraith discussed the growing gap between the increasing private wealth in the u.s. and the stagnant condition of resources allocated to the public sector.

What will not cause political parties to change or develop

Did the spanish settlers and missions have a positive effect on world history? why, what did they do that was positive? why was the treaty of paris (1763) good for the world/world history? did the plymouth colony have a positive effect on world history? why, what did they do that was positive?