Published on September 19, 2014
91 1830 Andrew Jackson signs the Indian Removal Act. Watch the videos to learn more about American history from 1815 to 1860. 1830184018501860 1843 Marcus Whitman leads at least 900 people over the Oregon Trail. 1846 U.S. declares war on Mexico; the same year, American settlers declare a Republic of California. 1853 The Gasden Purchase further expands U.S. southwestern lands. 1833 Slavery is abolished throughout the British Empire. 1845 Ireland’s potato crop is devastated by blight. 1857 A new constitution returns Mexico to a federal system of government. 1859 Charles Darwin’s On the Origin of Species is published. History's Impact video program 1836 Texas gains independence from Mexico.