Read the passage below carefully:
Historically, the Trans-Saharan trade routes served as vital economic lifelines connecting West Africa with North Africa and the Mediterranean. Initially, commerce relied on indigenous exchange networks trading local commodities such as salt, gold, and agricultural produce. As camel caravans became widely adopted, merchants successfully expanded these networks across the vast Sahara Desert, significantly increasing the volume and reach of commerce. Consequently, major urban trading centers like Timbuktu and Kano emerged, transforming modest settlements into flourishing hubs of wealth, Islamic scholarship, and administrative culture. Ultimately, the influx of economic prosperity and cross-cultural exchange laid the structural foundation for powerful medieval West African empires.
Arrange the summary points below in the logical sequence that reflects the author's progression of central arguments.
- 1Local exchange networks originally centered on trading essential commodities like gold and salt.
- 2The introduction of camel caravans facilitated long-distance commerce across the Sahara Desert.
- 3Expanded commercial routes led to the growth of prominent urban centers of trade and scholarship.
- 4Economic wealth and cultural exchange ultimately fostered the rise of major West African empires.