England declares war against Spain 313 Rapid conquest of French and Spanish colonies 314 French and Spaniards invade Portugal 316 The invasion repelled by England 316 Severe reverses of the Spaniards in all quarters 316 Spain sues for peace 317 Losses of British mercantile shipping 317 Increase of British commerce 318 Commanding position of Great Britain 319 Relations of England and Portugal 320 Terms of the Treaty of Paris 321 Opposition to the treaty in Great Britain 322 Results of the maritime war 323 Results of the continental war 324 Influence of Sea Power in countries politically unstable 324 Interest of the United States in the Central American Isthmus 325 Effects of the Seven Years' War on the later history of Great Britain 326 Subsequent acquisitions of Great Britain 327 British success due to maritime superiority 328 Mutual dependence of seaports and fleets 329 CHAPTER IX. COURSE OF EVENTS FROM THE PEACE OF PARIS TO 1778.--MARITIME WAR CONSEQUENT UPON THE AMERICAN REVOLUTION.--SEA BATTLE OFF USHANT.