Achondroplasia is one of the most common types of dwarfism. Learn about its causes, diagnosis, and treatment. Achondroplasia is one of the most common types of dwarfism.
Westward Expansion (1807-1912) The Surge West. Summary. The westward movement of the American population occurred in intermittent flurries of settlement. The first began early in the nation's history, resulting in the statehood of Vermont, Kentucky, Tennessee, and Ohio, all of which were admitted to the Union between 1791 and 1803.
1841: Oregon Trail-People begin to travel west in wagon trains on the Oregon Trail. Around 300,000 people would take the trail over the next 20 years. 1845: Manifest Destiny-Journalist John O'Sullivan first uses the term Manifest Destiny to describe the westward expansion of the United States.