Why did trade begin across the sahara desert? (minimum a paragraph)

Hello!

Trade began in 1000 BC when two regions desired salt and gold. Gold and salt fueled the economy of the Saharan region. It was not a single path, it was branching and has multiple trading centers scattered across it. It also went through cities! 

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The way this small state - large state compromise guards against tyranny is that small states and large states have one note: i am sorry but i was not able to give you the full answer. but i got this answer from

Transcontinental railroad was the most effective way to travel.