Answer:
The most convincing 'internal' factor behind southern defeat was the very institution that prompted secession: slavery. Enslaved people fled to join the Union army, depriving the South of labour and strengthening the North by more than 100,000 soldiers. Even so, slavery was not in itself the cause of defeat.
respuesta: Con las herramientas de metal se producían más alimentos. El comercio apareció porque la gente se aburría. En la Edad de los Metales se inventó el carro y el barco de vela.
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