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
West Florida Controversy bear in mind that in the transfer [of Louisiana to the United States] the identical language was employed that had been used in 1800, so that the government of the United States was subrogated, in express terms, to the rights of France and of Spain. … The United States insisted that by the treaty of 1800 Spain ceded the disputed territory [of West Florida], as part of Louisiana, to France, and that France, in turn, in 1803, ceded it to the United States. Spain, with equal earnestness and persistence, maintained that her cession to France comprehended what was at that