Civilizations of the Fertile Crescent: The Phoenicians
The Phoenicians were known as the greatest sea traders on the Mediterranean, and left their legacy by creating the alphabet we still use today (with a few changes). From their bases in what is today Lebanon, the Phoenicians traveled the entire length of the Mediterranean, setting up far away colonies in places like Spain and North Africa. Their colony of Carthage actually challenges the powerful Roman Republic for dominance of the region in the third and fourth centuries B.C.
The Phoenicians built much of their wealth on selling a very special purple dye made from the shell of the murex, a snail-like creature. This dye was so valuable that in ancient Rome, only the emperor was allowed to wear all purple, and the noble families of Rome marked their togas with a purple stripe.
Sources for information about the Phoenicians:
Wikipedia Entry (a good starting point)
Ancient History Encyclopedia: Phoenicia
History World: Phoenicians
History for Kids: Phoenicians