Please help this is a final Will give

According to Lincoln, what was the main reason for fighting the Civil
war?

To preserve the Union.

To show the strength of the United States to other nations.

slavery

To show the south his
power as president.

Slavery, Lincoln stated, was the reason for the war: One eighth of the whole population were colored slaves. Not distributed generally over the Union, but localized in the Southern part of it. ... To say that slavery was the cause placed responsibility for the bloodshed on the South.

d) he bring down boss tweed and tammany hall.