Who were the authors of the marshall plan?

Ahistorian studying urban history in chicago in in the early 1900's. she is studying the population changes and the activities that people did in their everyday lives. based on the description which school of thought does the historian likely belong to

The development of humans was directly dependent ondevelopment of a language.development of communication between people.e development of tools.litdevelopment of the wheel.

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more.b-it made cross-country travel too expensive for ordinary americans.c-it decreased the safety of americans who moved to settle the plains.d-it shortened travel time between the east and west for all americans.