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
France in the Seven Years' War to suffer defeats throughout 1762 eventually forcing them to sue for peace. The 1763 Treaty of Paris confirmed the loss of French possessions in North America and Asia to the British. France also finished the war with very heavy debts, which they struggled to repay for the remainder of the 18th century. The previous major conflict in Europe, the War of the Austrian Succession, ended in 1748 with the Treaty of Aix-la-Chapelle. This peace agreement was very unpopular with the French populace who saw the terms as excessively lenient to France's enemies, specifically Britain and the Dutch Republic, and many