1) The document discusses how the Americas changed in the 19th century, with the U.S. experiencing westward expansion and the Civil War over slavery, Canada establishing itself as a federal dominion, and Latin America forming smaller unstable states.
2) It also covers frontier events like the Louisiana Purchase doubling U.S. size, the Haitian Revolution ending slavery in Haiti, and explorations of newly acquired U.S. lands.
3) The Battle of Antietam in 1862, which had the highest single-day death toll in American history, allowed Lincoln to issue the Emancipation Proclamation and arrest Confederate momentum, changing the course of the Civil War and abolishing slavery