Difficult as this riddle was, it made but a part of the problem. France had no direct means of controlling American policy. Within the last four years she had tried to dictate, and received severe discipline. If France was a political factor of the first class in Jefferson’s mind, it was not because of her armies or fleets, or her almost extinguished republican character, or her supposed friendship for Jefferson’s party in its struggle with Anglican federalism. The 18th Brumaire severed most of these sentimental ties. The power which France wielded over American destinies sprang not from any direct French interest or fear of French arms, but from the control which Napoleon exercised over the Spanish government at Madrid. France alone could not greatly disturb the repose of Jefferson; but France, acting through Spain on the hopes and fears of the Southern States, exercised prodigious influence on the Union. Don Carlos IV. reigned at Madrid,--a Bourbon, but an ally of the French republic, and since the 18th Brumaire a devoted admirer of the young Corsican who had betrayed the republic. So far as Don Carlos was king of Spain only, his name meant little to Americans; but as an American ruler his empire dwarfed that of the United States. From the sources of the Missouri and Mississippi to the borders of Patagonia, two American continents acknowledged his rule. From the mouth of the St. Mary’s, southward and westward, the shores of Florida, Louisiana, Texas, and Mexico were Spanish; Pensacola, Mobile, and New Orleans closed all the rivers by which the United States could reach the gulf. The valley of the Ohio itself, as far as Pittsburg, was at the mercy of the King of Spain; the flour and tobacco that floated down the Mississippi, or any of the rivers that fell into the Gulf, passed under the Spanish flag, and could reach a market only by permission of Don Carlos IV. Along an imaginary line from Fernandina to Natchez, some six hundred miles, and thence northward on the western bank of the Mississippi River to the Lake of the Woods, some fourteen hundred miles farther, Spanish authority barred the path of American ambition. Of all foreign Powers Spain alone stood in such a position as to make violence seem sooner or later inevitable even to the pacific Jefferson; and every Southern or Western State looked to the military occupation of Mobile, Pensacola, and New Orleans as a future political necessity.