The colonies of Canada, Nova Scotia and New Brunswick unite as the Dominion of Canada, the beginning of the modern Canadian state.
The United States signs a treaty to buy Alaska from the Russian Empire for $7.2 million.
James Clerk Maxwell publishes "A Dynamical Theory of the Electromagnetic Field", unifying electricity, magnetism and light.
General Robert E. Lee surrenders to General Ulysses S. Grant, effectively ending the American Civil War.
John Wilkes Booth shoots President Lincoln at Ford's Theatre days after the Civil War effectively ends; Lincoln dies the next morning.
The Thirteenth Amendment to the US Constitution is ratified, formally abolishing slavery throughout the country.
The golden spike is driven at Promontory Summit, Utah, completing the first transcontinental railroad in the United States.