Which is the best measurement to use to determine who might have the absolute advantage? high opportunity cost low opportunity cost low efficiency high efficiency

Why was it difficult fpr unions to succeed in the 1800s

The revolutions in latin america in the 19th century resulted in political independence from europe the end of slavery in each country the establishment of stable democracies social and economic equality for all

Was the civil war inevitable? could anything have been done through compromise to stop it, or did it have to happen?