Amelia Island, at the mouth of the St. Mary's River in Florida, had long been the resort of lawless men, among whom were European adventurers attracted by the South American revolution, and many fugitive slaves from Defection of Spanish colonies Georgia and South Carolina. A plan was formed to organize a revolution on that island and to add Florida to the revolting South American republics. The forces gathered there became too strong for the Spaniards, and President Monroe decided to interfere. Gaines was sent to Amelia Island; but before he arrived, Aury, the commander of the malcontents, had surrendered to Commodore Henley. General Jackson, who was operating in those parts against the Seminoles, declared that "the cause of the United States must be carried to any point within the limits of Florida where an enemy is permitted to be protected." All eastern Florida, he set forth to the President, should be seized when Amelia Island was taken, and should be held as an indemnity for the outrages of Spain upon American citizens. This plan, Jackson said, could be carried out without implicating the United States. "Let it be signified to me that the province of Florida would be desirable to the United States, and in sixty days it will be accomplished."

Andrew Jackson in Florida

When the order to assume command reached Jackson, he raised a volunteer force in Tennessee from among his old soldiers. With these and the troops left by Gaines he marched into Florida. On the site of the Negro fort he built Fort Gadsden. He then advanced to the Bay of St. Marks, defeating the few Seminoles whom he encountered. On April 7, he raised the American flag there in place of the standard of Spain. Two Seminole chiefs who had taken refuge on an American vessel in the bay, and who were supposed to have participated in the massacre of a party of Americans, were brought on shore and hanged. Leaving a strong garrison at St. Marks, Jackson marched a hundred miles to the Indian town of Suwanee, where he hoped to capture Billy Bowlegs and his band. But the Indians, warned of his approach, Summary military measures escaped across the river. Suwanee was destroyed. Jackson, when at St. Marks, had taken prisoner one Arbuthnot, a Scotchman and supposed Indian sympathizer, whom he ordered to be confined until his return. At Suwanee, Captain Ambrister, a former English officer, intending to join the Indians, blundered into Jackson's camp, and was held a prisoner. On his return, Jackson ordered the two men to be tried by court-martial, on the charge of warning the Indians of the approach of the American soldiers, and both were convicted and executed. Jackson, on reaching Fort Gadsden, received from Pensacola occupied the Spanish Governor of Pensacola a protest against his invasion. He turned back, occupied Pensacola, and took the Fort of Carrios De Barrancas, to which the governor had fled.

When the news of Jackson's course reached Washington, Congress engaged in a heated debate over his occupation of the forts of a friendly power. In defending himself Jackson wrote that the Secretary of War had given him full power to conduct the campaign in the manner which seemed best. Spain, he claimed, had failed to fulfil that article of the treaty by which she was bound to restrain the Florida Indians from hostilities. Popular feeling Jackson unrebuked proved too strong for Congress to assert its privileges as the sole war-making power. Jackson was not even rebuked for his course. During all those months, Onis, the Spanish Minister, and Adams were in negotiation over a treaty, which was not ratified until two years later. Florida was to be ceded to the United States on a payment of $5,000,000, to be applied in satisfying the claims of American citizens against Spain. The Sabine River, instead of the Rio Grande, was made the dividing line between the United States and Spanish territory. The line was to run from the mouth of the An amicable settlement Sabine to the 32d parallel, thence north to the Red River and along it to the 100th meridian, thence north to the Arkansas and along that river to its source on the 42d parallel, and thence west to the Pacific. War with Spain was thus averted.

While the Florida question was under consideration, there arose another far more momentous to America. Free labor in the North and slave labor in the South were brought squarely face to face. Slave labor was fast rising in value. The new lands of the lower Mississippi opened a vast field for the employment of slaves in the production of cotton, sugar and tobacco. It was The slavery issue believed the extension of slavery into that new territory would save it from gradual extinction. The interstate traffic in slaves was viewed with abhorrence by many leading men in the South. John Randolph, while upholding slavery, denounced the traffic that was carried on in the Southern plantations. On the other hand it was seen that compromise would be of little value if the North only was to be permitted to increase its power by the admission of new States. New slave States as well were demanded by the Southerners.

In March, the citizens of Missouri had asked permission to form a State constitution and to be admitted into the Union. It was tacitly understood that slavery might be carried into territory east of the Mississippi belonging originally to the existing slave States. But Louisiana, west of the Mississippi, belonged to the whole of the United States rather than to any one of the several States. The question now arose whether Congress should establish slavery anew in territory of the United States. The Contention over Missouri alternative was presented to the people of the North whether to submit to the demands of the South or to consent to a dissolution of the Union. Though represented by a majority in Congress, the Northern States were defeated after a long struggle. John Quincy Adams doubted if Congress, under the American Constitution, had the right to prohibit slavery in a territory where it already existed. "If a dissolution of the Union should result from the slave question," he wrote, "it is obvious that it must shortly afterward be followed by a universal emancipation of the slaves."

During this same year Congress first granted pensions to needy veterans of American Pension system inaugurated the Revolutionary War and soon afterward to the widows and children of dead soldiers. Thus began the system of American pension legislation for former American soldiers which was destined to grow to such gigantic proportions in later years. Up to that time the number of stripes in the American flag had been eighteen. Now a bill was approved reducing the number of stripes to thirteen, the number of original States comprising the Union. The number of stars was to be made equal to that of the States. Soon afterward, the new flag, with twenty stars in its quartering, was first raised over the halls of Congress. Shortly after this the Fifteenth Congress adjourned. On October 20, a convention with Great Britain was signed respecting fisheries and boundaries, giving to Americans the right to fish in Newfoundland waters and renewing the agreement of 1815, making the 49th Oregon in dispute parallel the boundary between the United States and British North America. The convention also provided for the joint occupation of Oregon for ten years longer.

The glossy finish to leather known as "patent" leather was first patented in this year. Another notable invention of the time was the process of engraving on soft steel.

Illinois a State

The second session of the American Congress was not called until late in the year. Illinois was then admitted as the twenty-first State of the Union.