1776 - The amended Declaration of Independence, prepared by Thomas Jefferson, was approved and signed by John Hancock, the President of the Continental Congress in America.
1802 - The U.S. Military Academy officially opened at West Point, NY.
1803 - The Louisiana Purchase was announced in newspapers. The property was purchased, by the U.S. from France, was for $15 million (or 3 cents an acre). The "Corps of Discovery," led by Meriwether Lewis and William Clark, began the exploration of the territory on May 14, 1804.
1817 - Construction began on the Erie Canal, to connect Lake Erie and the Hudson River.
1848 - In Washington, DC, the cornerstone for the Washington Monument was laid.
1863 - The Confederate town of Vicksburg, MS, surrendered to General Ulysses S. Grant.
1886 - The first rodeo in America was held at Prescott, AZ.
1910 - Race riots broke out all over the United States after African-American Jack Johnson knocked out Jim Jeffries in a heavyweight boxing match.
1934 - At Mount Rushmore, George Washington's face was dedicated.
1939 - Lou Gehrig retired from major league baseball.
1957 - The U.S. Postal Service issued the 4¢ Flag stamp.
1959 - The 49-star U.S. flag was debuted.
1960 - The 50-star U.S. flag made its debut in Philadelphia, PA.
1976 - The U.S. celebrated its Bicentennial.
2009 - The Statue of Liberty's crown reopened to visitors. It had been closed to the public since 2001.