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On This Day
America250
— 250 years since 1776. Explore two and a half centuries of American history.
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Anniversaries in American history that fall on September 17.
1862 · Eras
Battle of Antietam
Bloodiest single day in American military history; 22,000 casualties
The Civil War
1862 · Events / Wars & Conflicts
Battle of Antietam
The bloodiest single day in American military history, September 17, 1862
Battle of Antietam
1787 · Documents / Founding Documents
U.S. Constitution
The 1787 framework of government that has governed the United States ever since
U.S. Constitution
1787 · Events / Milestones & Firsts
Constitutional Convention
The 1787 Philadelphia gathering that scrapped one government and invented another
Constitutional Convention