What effect did plessy v. ferguson have on jim crow laws?
a)it weakened the laws in southern states.
b)it weakened the laws in northern states.
c)it strengthened the laws throughout the united states.
d)it invalidated the laws throughout the united states.

The correct answer is C.

The Plessy v. Ferguson was a landmark case from the US Supreme Court, issued in 1896.

It confirmed that segregated facilities were not violating the US constitution as long as the ones for whites and the ones for black citizens were equal in quality. From this decision, the principle "separate but equal" was derived.

It actually gave legitimacy to the Jim Crow laws that many Southern States were enacting, and which promoted segregation and indirect discriminations.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.