Glaucoma damages the eye’s optic nerve and is the leading cause of blindness in the United States. Source: National Library of Medicine

On this date in 1804, Alexander Hamilton and Aaron Burr dueled with pistols in Weehawken, N.J. Source: PBS

On this date in 1890, Wyoming became the 44th state. Source: Wyoming Chambers of Commerce

While a student at Yale University, George H.W. Bush played first base on a team that twice went to the College World Series. Source: WhiteHouse.gov

When the clock hits 34 minutes and 56 seconds past noon today (7/8/09), the time and date together will be 123456789. Source: Politico.com

President Gerald Ford was born Leslie Lynch King Jr. in 1913. His name wasn’t legally changed to Gerald R. Ford until 1935. Source: Gerald R. Ford Presidential Library & Museum

In July 1776, an estimated 2.5 million people lived in the United States. Source: Census Bureau

At 26, Edward Rutledge of South Carolina was the youngest signer of the Declaration of Independence. Benjamin Franklin, age 70, was the oldest signer. Source: Independence Hall Association

In 2007, $4.7 million worth of American flags were imported by the United States, the vast majority of that amount ($4.3 million) from China. The U.S. exported $2.4 million in U.S. flags that year, with half going to Mexico. Source: Census Bureau

There is a greater than 1 in 4 chance that hot dogs and pork sausages served at picnics this weekend in the U.S. originated in Iowa. Source: Census Bureau