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Philadelphia committee
Philadelphia committee led by Benjamin Franklin attempts to regulate waste disposal and water pollution. -
Constitution of the United States
Pursuant to Article V of the United States Constitution, Congress proposed and the states ratified the first 10 amendments now known as the Bill of Rights. -
Whiskey Rebellion
As the new country began finding its feet, U.S. President George Washington sent troops to western Pennsylvania in 1794 to quell the Whiskey Rebellion, an uprising by citizens who refused to pay a liquor tax that had been imposed by Secretary of Treasury Alexander Hamilton to raise money for the national debt and to assert the power of the national government. -
Henry David Thoreau published Walden
Henry David Thoreau published Walden -
Dred Scott Decision
The 1850s were awash in harbingers of the American Civil War—from the Compromise of 1850, which temporarily forestalled North-South tensions, to John Brown’s Harpers Ferry Raid, which ramped them up. -
Battle of Gettysburg
In July 1863, the year of the Emancipation Proclamation, in the small Pennsylvania crossroads town of Gettysburg, Robert E. Lee’s invading Army of Northern Virginia sustained a defeat so devastating that it sealed the fate of the Confederacy -
Ernst Haeckel
The term ecology is coined in German as Oekologie by Ernst Heinrich Philipp August Haeckel -
Robert Angus Smith
The term acid rain is coined by Robert Angus Smith in the book Air and Rain -
Battle of the Little Bighorn
While the country celebrated its anniversary at the Philadelphia Centennial Exposition, on June 25, 1876, the 7th Cavalry under the command of Lieutenant Colonel George Armstrong Custer was vanquished by Lakota and Northern Cheyenne warriors led by Sitting Bull in the Battle of the Little Bighorn. -
Plessy v. Ferguson
With the end of Reconstruction in the 1870s, the enactment of Jim Crow laws enforced racial segregation in the South. -
Henry Antoine Des Voeux
The term smog is coined by Henry Antoine Des Voeux in a London meeting to express concern over air pollution -
The Organic Act
US Congress created the National Park Service -
Stock Market Crash
With the American economy humming during the Roaring Twenties, peace and prosperity reigned in the United States…until it didn’t. The era came to a close in October 1929 when the stock market crashed, setting the stage for years of economic deprivation and calamity during the Great Depression. -
The Atomic Bombing of Hiroshima and Nagasaki
Having again stayed out of the initial stages of a worldwide conflict, the U.S. entered World War II on the side of the Allies following the Japanese attack on Pearl Harbor. -
Silent Spring
Rachel Carson published Silent Spring -
Assassination of Martin Luther King, Jr.
At the center of the widespread social and political upheaval of the 1960s were the civil rights movement, opposition to the Vietnam War, the emergence of a youth-oriented counterculture, and the establishment and reactionary elements that pushed back against change. -
Apollo 8
The Apollo 8 picture of Earthrise -
The First Earth Day
Millions of people gather in the United States for the first Earth Day. US Environmental Protection Agency established -
Montreal Protocol
Montreal Protocol on substances that deplete the ozone layer entered into force -
The Kyoto Protocol
The Kyoto Protocol was negotiated in Kyoto, Japan in December. Countries commit to reduce their emissions of carbon dioxide -
Kyoto Protocol Ends
U.S. rejects the Kyoto Protocol -
September 11 Attacks
When Islamist terrorists crashed hijacked planes into the World Trade Center in New York City, the Pentagon in Washington, D.C., and the Pennsylvania countryside, resulting in the deaths of nearly 3,000 people. -
Paris Agreement
U.S. announces it will cease participation in the Paris Agreement on climate change mitigation -
Paris Agreement
U.S. announces it will rejoin the Paris Agreement on climate change mitigation