This incident marked an epoch in the history of the West, where the first steamboat was built in 1811. Within a few years, they were plying on all the important rivers, greatly assisting emigration and the development of the country. The first steamer to cross the Atlantic was the _Savannah_ in 1819. The screw propeller was introduced by the great Swedish inventor, John Ericsson, in 1836. Really successful ocean navigation began in 1838, when the _Sirius_ and _Great Western_ made the voyage from England to the United States. [Illustration: ROBERT FULTON.] OPPRESSIVE COURSE OF ENGLAND. The devastating war raging between England and France was destructive to American commerce and interests. The star of the wonderful Napoleon Bonaparte was rapidly in the ascendant, and his marvelous military genius seemed to threaten the "equilibrium of the world." England had no love for the United States and played havoc with our shipping. Her privateers infested our coasts, like swarms of locusts. Because of her immense naval superiority, she pestered us almost beyond bearing. She stopped our vessels off-shore, followed them into rivers and harbors, overhauled the crews, and in many cases took sailors away under the plea that they were English deserters. Her claim was that "once a British subject, always a British subject;" no sworn allegiance to any other government could release the claim of England upon him. Our vessels were prohibited from carrying imports from the West Indies to France, but evaded the law by bringing imports to this country and then reshipping them to France. England peremptorily ordered the practice to stop and declared that all vessels thus engaged should be lawful prizes to her ships. This action caused general indignation in this country and thousands of citizens clamored for war. Jefferson never lost his self-poise. While a thorough patriot, he knew the meaning of war. He sent a message to Congress on the subject in January, 1806, and the question was one of earnest and prolonged discussion, ending in the adoption of a resolution to prohibit certain articles of British manufacture. But matters rapidly grew worse. In May following England declared the coast of Europe, from the Elbe in Germany to Brest in France, in a state of blockade. Bonaparte retaliated with the famous Berlin Decree, which blockaded the British Islands. In the spring of 1807 the British ship _Leander_ fired into a coasting vessel and killed one of the men. The President issued a proclamation forbidding the _Leander_ and the two ships in her company from entering any of the waters of the United States; calling upon all officers to apprehend the captain of the _Leander_ on a charge of murder; prohibiting all communication between the shore and the ships, and warning all citizens from giving them aid under penalty of the law. Envoys were sent to England to adjust the trouble, but their efforts came to naught. THE AFFAIR OF THE LEOPARD AND CHESAPEAKE.