When it was manifest destiny. The gold rush made them rich
Answer:
The legal state of slaves was based on the fact that the slave was not a subject but an object of law
Many Americans were against getting involved in a War that was being fought in Europe though begrudgingly Americans became aware there was danger on the High Seas as Atlantic waters became host to submarines while warships dueled in the waters of the South Pacific and Atlantic.
Many Americans, particularly the Wobbles, the IWW International Workers of World (rightly) argued that the main reason for fighting would be to profit by various means profits that would mostly land in the pockets of International Bankers and Industrialist, the Halliburton of the times.