2. In December of 1817 Mississippi was organized and admitted into the Union. The new State came with a population of sixty-five thousand souls. At the same time the attention of the government was called to a nest of pirates on Amelia Island, off the coast of Florida. An armament was sent against them, and the lawless establishment was broken up. Another company, on the island of Galveston, was also suppressed. 3. The question of internal improvements now began to be agitated. Without railroads and canals the products of the interior could never reach a market. Whether Congress had a right to vote money to make public improvements was a question of debate. Among the States, New York took the lead in improvements by constructing a canal from Buffalo to Albany. The cost of the work was nearly eight million dollars. [Sidenote: Trouble with the Seminoles.] 4. In 1817 the Seminole Indians of Georgia and Alabama became hostile. Some negroes and Creeks joined the savages in their depredations. General Jackson was ordered to reduce the Indians to submission. He mustered a thousand riflemen from Tennessee, and in the spring of 1818 completely overran the hostile country. [Sidenote: The Cession of Florida.] 5. While on this expedition, Jackson took possession of St. Mark's. The Spanish troops stationed there were removed to Pensacola. Two Englishmen, named Arbuthnot and Ambrister, charged with inciting the Seminoles to insurrection, were tried by a court-martial and hanged. Jackson then captured Pensacola, and sent the Spanish authorities to Havana. The enemies of General Jackson condemned him for these proceedings, but the President and Congress justified his deeds. The king of Spain now proposed to cede Florida to the United States. On the 22d of February, 1819, a treaty was concluded at Washington City by which the whole province was surrendered to the American government. The United States agreed to relinquish all claim to Texas, and to pay to American citizens, for depredations committed by Spanish vessels, five million dollars. [Sidenote: New States.] 6. In 1818 Illinois, the twenty-first State, was organized and admitted into the Union. The population of the new commonwealth was forty-seven thousand. In December of 1819 Alabama was added, with a population of one hundred and twenty-five thousand. About the same time Arkansas Territory was organized. In 1820 the province of Maine was separated from Massachusetts and admitted into the Union. The population of the new State had reached two hundred and ninety-eight thousand. In August of 1821 Missouri, with a population of about seventy-four thousand souls, was admitted as the twenty-fourth member of the Union. [Sidenote: The Missouri Compromise.]