1860 - Republican candidate Abraham Lincoln is elected as president, pledging to oppose the spread of slavery.

The Pony Express makes its first delivery of mail, travelling 1,966 miles from St Louis to Sacramento in 11 days. But the completion of a transcontinental telegraph line signals the end for the Pony Express.

1861 - 11 pro-slavery southern states break away from the union and form the Confederate States of America under the leadership of Jefferson Davis, triggering a civil war with abolitionist northern states.

The first shots are fired by Confederate forces on Fort Sumter in Charleston, South Carolina.

1862 The Homestead Act allows settlers to claim up to 160 acres of land after living on it for five years.

1864 8,000 Navajo Indians are forcibly marched across New Mexico to a reservation on the "Long Walk".

1865 - Confederate forces are defeated, but Lincoln is assassinated. The 13th Amendment abolishes slavery and the Ku Klux Klan, a white supremacist group, is founded.