Political opponents of President John Adams opposed the Alien Enemies Act of 1798 because it stripped American citizens of the right to free speech, which blatantly violated the Constitution.
The Triangle Trade brought labor for a <em>very</em> cheap price, much much cheaper than indentured servants. They also began to use the triangle trade instead of enslaving the locals because the natives knew their way around the land and could run away easily.
Increasing the amount of well nourished workers for the factories during the industrial revolution