Meanwhile the war with Great Britain was entering a new and threatening phase.  No notable successes had been achieved on land, and repeated attempts to reduce Canada had signally failed.  On the Great Lakes and the high seas the navy had won glory, but only a handful of privateers was left to keep up the fight.  The collapse of Napoleon’s power had brought a lull in Europe, and the British were free to concentrate their energies as never before on the conflict in America.  The effects were promptly seen in the campaign which led to the capture of Washington and the burning of the Federal Capitol in August, 1814.  They were equally manifest in a well-laid plan for a great assault on the country’s southern borders and on the great Mississippi Valley beyond.

The last-mentioned project meant that, after two years of immunity, the Southwest had become a main theater of the war.  There was plenty of warning of what was coming, for the British squadron intended for the attack began assembling in the West Indies before the close of summer.  No one knew, however, where or when the blow would fall.  To Jackson the first necessity seemed to be to make sure of the defenses of Mobile.  For a time, at all events, he believed that the attack would be made there, rather than at New Orleans; and an attempt of a British naval force in September to destroy Fort Bowyer, at the entrance to Mobile Bay, confirmed his opinion.

But the chief attraction of Mobile for the General was its proximity to Florida.  In July he had written to Washington asking permission to occupy Pensacola.  Months passed without a reply.  Temptation to action grew; and when, in October, three thousand Tennessee troops arrived under one of the subordinate officers in the recent Creek War, longer hesitation seemed a sign of weakness.  Jackson therefore led his forces against the Spanish stronghold, now in British hands, and quickly forced its surrender.  His men blew up one of the two forts, and the British blew up the other.  Within a week the work was done and the General, well pleased with his exploit, was back at Mobile.

There he found awaiting him, in reply to his July letter, an order from the new Secretary of War, James Monroe, forbidding him to touch Pensacola.  No great harm was done, for the invaded territory was no longer neutral soil, and the task of soothing the ruffled feelings of the Spanish court did not prove difficult.

As the autumn wore on, signs multiplied that the first British objective in the South was to be New Orleans, and no efforts were spared by the authorities at Washington to arouse the Southwest to its danger and to stimulate an outpouring of troops sufficient to repel any force that might be landed at the mouth of the Mississippi.  On the 21st of November, Jackson set out for the menaced city.  Five days later a fleet of fifty vessels, carrying ten thousand veteran British troops under command of Generals Pakenham and Gibbs, started from Jamaica for what was expected to be an easy conquest.  On the 10th of December the hostile armada cast anchor off the Louisiana coast.  Two weeks later some two thousand redcoats emerged from Lake Borgne, within six or seven miles of New Orleans, when the approach to the city on that side was as yet unguarded by a gun or a man or an entrenchment.