September 17 has been a day of profound significance in both world history and sports. From the founding of a nation's government to the establishment of major sports leagues and individual athletic feats, the date is marked by a wide range of notable events.

In History

• 1787: The U.S. Constitution Is Signed. The U.S. Constitution was signed by 39 delegates at the Constitutional Convention in Philadelphia, laying the groundwork for the modern American government and replacing the Articles of Confederation. This event is commemorated annually on this date as Constitution Day.

• 1849: Harriet Tubman's Escape. The famous abolitionist Harriet Tubman made her first successful escape from slavery in Maryland, beginning her heroic work as a "conductor" on the Underground Railroad, through which she guided hundreds of others to freedom.

• 1862: The Battle of Antietam. The Battle of Antietam, fought near Sharpsburg, Maryland, was the bloodiest single-day battle in American history. While a tactical draw, it was a strategic Union victory that halted General Robert E. Lee's first invasion of the North and gave President Abraham Lincoln the confidence to issue the preliminary Emancipation Proclamation.

• 1939: The Soviet Union Invades Poland. In the early stages of World War II, the Soviet Union invaded Poland from the east, fulfilling the secret terms of the Molotov-Ribbentrop Pact with Nazi Germany and effectively ending Poland's resistance.

• 1978: The Camp David Accords Are Signed. Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin signed the Camp David Accords at the White House. This peace treaty, brokered by U.S. President Jimmy Carter, led to a peace agreement between the two nations after decades of conflict.

• 1983: Vanessa Williams Is Crowned Miss America. Vanessa Williams became the first Black woman to win the Miss America title.

In Sports

• 1920: The National Football League Is Founded. In a historic meeting at an automobile showroom in Canton, Ohio, the American Professional Football Association (APFA), the precursor to the NFL, was formed.

• 1938: Don Budge Completes the Grand Slam. American tennis player Don Budge became the first person to achieve the calendar-year Grand Slam in men's tennis, winning the U.S. Lawn Tennis Association championships.

• 1954: Rocky Marciano's Unbeaten Streak Continues. Heavyweight boxing champion Rocky Marciano knocked out Ezzard Charles to retain his title, moving one step closer to his undefeated 49-0 record.

• 1984: Reggie Jackson Hits His 500th Home Run. "Mr. October" became the 13th player in MLB history to hit 500 home runs.

• 2004: Barry Bonds Hits His 700th Home Run. The San Francisco Giants slugger joined Babe Ruth and Hank Aaron as the only players in Major League Baseball history to reach the 700-home run milestone.