Traveling merchants were a major vehicle for creating vast
             interregional networks and trade routes in the great overland oceanic
             networks increased in importance (Interregional Pp). Transportation was an
             important factor, whether meaning better ships and navigation, or the
             increasingly widespread use of the camel as a ship of the desert (Tropical
             Pp). Before the 1st millennium CE, the Sahara was an almost impassable
             barrier separating the North African coast from sub-Saharan Africa
             (Tropical Pp). And the Atlantic Ocean not a highway for travel, but a
             barrier (Tropical Pp). The only route connecting the two areas was the
             Nile, however, in its southern reaches travel was made difficult by both
             rapids and surrounding jungle (Tropical Pp).
             The monsoon winds were the propulsion for ships, the driving force
             for navigation in the Indian Ocean, blowing ships northeast in summer, and
             then back southwest in winter (Tropical Pp). Indian Ocean trade first
             increased under local groups from southern Arabia, India, and Southeast
             Asia, then outside groups, such as the Chinese became involved and a
             network establishing a link between East African commercial city-states and
             the Middle East, India, and Southeast Asia (Interregional Pp). By the 16th
             century, the Portuguese dominated this system and linked it directly,
             rather than through Mediterranean intermediaries, with Europe
             (Interregional Pp). Although products, such as spices from Southeast Asia
             and other expensive goods, continued to be exchanged, bulk good such as
             sugar and textiles were increasingly involved (Interregional Pp).
             With the introduction of the camel, the Sahara was no longer a
             barrier and people and trade good as well as warriors, could travel quickly
             across the desert (Tropical Pp). This transformed life in the West African
             grasslands because camel caravans that crossed the Sahara came primarily to
             ...