St. Louis became the center of a regional fur trade with Native American tribes that extended up the Missouri and Mississippi rivers, which dominated the regional economy for decades. Trading partners of major firms shipped their furs from St. Louis by river down to New Orleans for export to Europe. They provided a variety of goods to traders for sale and trade with their Native American clients. The fur trade and associated businesses made St. Louis an early financial center and provided the wealth for some to build fine houses and import luxury items. Its location near the confluence of the Illinois River meant it also handled produce from the agricultural areas. River traffic and trade along the Mississippi were integral to the state's economy. As the area's first major city, St. Louis expanded greatly after the invention of the steamboat and the increased river trade.