The answer is "homophily".
Homophily refers to the inclination of people to partner and bond with comparative others. The presence of homophily has been found in an immense range of system considers.People in homophilic connections share regular attributes (convictions, values, training, and so forth.) that make correspondence and relationship arrangement simpler. The inverse of homophily is heterophily.
Answer:
The expansion of railroads impacts the development of the United States by creating jobs, establishing a national market, establishing a cattle industry on the Plains, and allowing certain people to acquire great wealth through investing in the railroad.
