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
History of St. Louis (1763–1803) service of Jean Francois Le Dee and Pierre Laclède to build trading posts in the Illinois Country. Fur trading was becoming a more lucrative profession and many more started to travel up the Mississippi River for the same reason. Shortly before the upriver departure of Laclède in August 1763, word arrived that France had ceded its territory on the east bank of the Mississippi to Great Britain according to the Treaty of Paris (1763), giving new significance to the trading posts on the west bank. The group led by Laclède included his young stepson Auguste Chouteau and roughly twenty boatmen