The Seven Years' War was a conflict between the powerful nations of Great Britain and France For Control of North America. Most European countries were involved as a result of alliances with one side or the other.
Great Britain wins and gains control of Canada and all land east of the Mississippi river.
Britain also receives Florida from Spain. In exchange the Spanish recieved control of Louisiana, the Mississippi River Delta, and the city of New Orleans.
The Eastern boundary of Spanish Texas becomes the Mississippi River.