1756 – The Seven Years’ War begins when Great Britain declares war on France.
1860 – Abraham Lincoln wins the Republican Party presidential nomination over William H. Seward, who later becomes the U.S. Secretary of State.
1896 – The Supreme Court rules in Plessy v. Ferguson that the “separate but equal” doctrine is constitutional.
1933 – President Franklin D. Roosevelt signs an act creating the Tennessee Valley Authority.
1953 – Jackie Cochran becomes the first woman to break the sound barrier.
1969 – Apollo 10 is launched.
1980 – Mount St. Helens erupts in Washington, killing 57 people and causing $3 billion in damage.