Colonial history of the United States Lower Louisiana. This vast tract was first settled at Mobile and Biloxi around 1700, and continued to grow when 7,000 French immigrants founded New Orleans in 1718. Settlement proceeded very slowly; New Orleans became an important port as the gateway to the Mississippi River, but there was little other economic development because the city lacked a prosperous hinterland. In 1763, Louisiana was ceded to Spain around New Orleans and west of the Mississippi River. In the 1780s, the western border of the newly independent United States stretched to the Mississippi River. The United States reached an agreement with Spain for
Spanish Empire and center was suppressed by a monarchy afraid of losing control. All was to be swept away by the tumult that was to overtake Europe at the turn of the 19th century with the French Revolutionary and Napoleonic Wars. The first major territory Spain was to lose in the 19th century was the vast and wild Louisiana Territory, which stretched north to Canada and was ceded by France in 1763 under the terms of the Treaty of Fontainebleau. The French, under Napoleon, took back possession as part of the Treaty of San Ildefonso in 1800 and sold it to the