Tired from a full day's work, Rosa Parks boarded a Montgomery bus on December 1, 1955. When she refused to obey the driver's order to give up her seat in the "colored" section for a white person, she was arrested for civil disobedience. Parks' act of defiance, and the Montgomery Bus Boycott that followed, are recognized as pivotal moments in the Civil Rights Movement.

 Todd Beamer and the Passengers of Flight 93: Fought Back Against 9/11 Terrorists

When account manager Todd Beamer and the other passengers on United Airlines Flight 93 realized their plane had been seized by terrorists, they worked quickly and courageously to reclaim control. Flight 93 crashed in a field in Shanksville, Pennsylvania, but the passengers' brave resistance galvanized America at its darkest moment since the attack on Pearl Harbor.

 Mohammed Bouazizi: Sparked a Revolution

Tunisian street vendor Mohammed Bouazizi never had any dreams bigger than saving enough money to rent or buy a pick-up truck. But when he set himself on fire out of desperation in December 2010, he became a symbol of the suffering of all Tunisians. Bouazizi's death inspired the nationwide unrest that resulted in the overthrow of Tunisian dictator Zine El Abidine Ben Ali. The Tunisian uprising, in turn, led to the Arab Spring movement that ultimately toppled regimes in Egypt and Libya.

 Candy Lightner: Stood Up Against Drunk Driving

After her 13-year-old daughter was killed by a repeat DWI offender, Candy Lightner founded Mothers Against Drunk Driving (MADD) in her home on March 7, 1980. Before MADD, there were little to no legal consequences for driving while intoxicated; her organization transformed American attitudes about drunk driving and successfully fought for stricter laws across the country. 

 J. K. Rowling: Inspired a New Generation of Readers

Newly divorced and struggling to make ends meet, single mom Joanne Rowling turned to work on the novel she had been outlining for five years. Harry Potter and the Sorcerer's Stone was published in 1997 under the name "J.K." Rowling—her publisher didn't believe a woman's name would appeal to young boys. Six books and 10 years later, Harry Potter has shattered sales records and enthralled millions of reader of all ages.

 Frank Willis: Did His Job...and Brought Down a President

On June 17, 1972, security guard Frank Willis was making his midnight rounds at the Watergate office building in Washington, D.C., when he noticed tape over the lock of a basement door. Thinking another worker had left it there accidentally, he removed it. Willis later found tape again in the same place. He called the police, and the rest is history. Two years later, President Nixon resigned in disgrace over his involvement in the coverup of the Watergate break-in.

 Ryan White: Raised Awareness of AIDS

Ryan White, a teen from Indiana, was a hemophiliac who contracted AIDS through a blood transfusion. He passed away at 18, with family and Elton John by his bedside. Through his struggle with the disease, White became the new face of the epidemic, debunking the myth that AIDS afflicted only drug users and the sexually promiscuous. His fight for fair and equal treatment from his public school system helped expose the discrimination faced by AIDS patients.

 Lilly Ledbetter: Fought for Equal Pay

Upon retiring from Goodyear after nearly 20 years, Lilly Ledbetter sued the company in 1998 for paying her less over the years than her male coworkers. The lawsuit climbed the judicial ladder until it reached the Supreme Court. Although they did not rule in her favor, Justice Ruth Bader Ginsberg wrote a stirring dissent. Congress subsequently passed the Lilly Ledbetter Fair Pay Act in 2009, changing federal law to better protect women in the workplace.