It changed them in many ways look up on google American civil war hope this helped
Answer:
They experienced a dreadful journey. The slaves were tightly packed into ships. There was not much fresh air to breathe and the stench was horrible. There was almost no room to move and many of the slaves wished for death. Illness was common and the white men would flog the slaves. Some were force fed and if they didn’t agree with eating, they would get whipped and cut. The African slaves had horrible experiences while crossing The Middle Passage.
Most of it was conquered from Mexico not bought, as a result of the Mexican War of 1846, the rest was I guess you could say "bought" through the Gadsden purchase for 10 million dollars.