1829-1851 2nd Cholera pandemic 1830-1860 Underground railroad leads 100,000+ slaves to freedom in US 1835-1842 2nd Seminole War 1837-1901 Reign of Queen Victoria (Hanover) 1839-1842Opium war between China and the English 1841-1844 John Tyler president of US 1842 Chinese cede Hong Kong to the English