How did railroads expand the western industries?

As more railroads were built, it helped to expand the nation and the West Industries cropped up in the West and used the railroads to link industry to markets in the Eastern part of the nation.

- "the civil rights movements"

- "following the american civil war and abolition of slavery, the united states entered a period known as reconstruction, during which black americans continued to suffer from disenfranchisement, racial segregation, and economic oppression. beginning in the early 1950's, black americans launched a series of major campaigns of civil resistance, emphasizing the need for nonviolent protests and civil disobedience."

"such as the montgomery bus boycott of 1955-56, a campaign launched by rosa parks against the policy of racial segregation of the public transit system in alabama. “sit-ins” became popular across the american south, particularly in greensboro, north carolina, increase national sentiment."

- "the counterculture movement"

- "counterculture began to develop in the united states following the rise of conformity in american culture during the 1950s. by 1963, youth, particularly those of the white middle class, began rejecting the cultural standards and normality of their parents, opting for progressive attitudes instead. the movement gained momentum as the civil rights movement became increasingly successful and as the u.s. military intervention of vietnam began to take a negative turn."

"hippie counterculture moved further into popular culture following the summer of love in 1967 when thousands of people came together in the haight-ashbury neighborhood of san francisco. along with greenwich village in new york city, haight-ashbury became a hub for the counterculture movement."

genetics is the study of how dna works, the methodologies defining the new recent technologies allow scientist to have a panoramic view of the entire dna landscape, especially how genomes interact with their environment, including off course, factors outside their organisms.

thus is very possible the existence of both scenarios, where populations of isolated individuals have different genetic traits, and share traits related to genetic mutation, due rats can easily travel overseas using human transport channels. so scientists could get a vast number of data, including human interaction, evolution of rodents, health development, spread of infections, development of new organisms, how genomes evolve in different environments and so on.