What was an effect of the marriage of King Ferdinand and Queen Isabella? A It increased fighting between the kingdoms in Spain.
B It united Christian kingdoms to form the country of Spain.
C It made it easier for the Umayyads to fight against Spain.
D It ended religious and political conflicts in Spain.

B It united Christian kingdoms to form the country of Spain.

Explanation:

King Ferdinand and Queen Isabella's marriage helped to unite Spain by the use of Catholicism.

They removed Muslims and News from their lands and began to have trials of heretics which helped consolidate their power base.

here are some major conflicts i found. maybe pick one and do more research on it. (cause i ain't writing 6 paragraphs)

in 1877, the nez perce war took place.

1881 - president james garfield was assassinated.

1882 - the chinese exclusion act was passed.

1883 - a decision in the civil rights cases legalized racial segregation in the united states.

1887 - the dawes act was passed.

1893 - the panic of 1893 took place. (what a creative name)

and there are probably other topics you can find if you just search up "united states timeline," or "conflicts in the 19th century for america."

then once you find a topic you like find out how it affected the people of america and what not. (sorry if this feels a bit short changed, history was and never will be one of my strong topics)