When Britain become an island?

Which of the following brought about the final settlement of the official boundary lines of the state of texas? the peace treaty of the mexican-american war the 1845 act signed by the president that made texas a state the reincorporation of texas at the end of the civil war the compromise of 1850

How did slavery end in the united statesa. it ended with the emancipation proclamationb. it ended when the union won the civil warc. it ended with the fifteenth amendmentd. it ended with the 13th amendment

Could anything have been done through compromise to stop it, or did it have to happen?