Here is a look back at the events of 2013.
Notable U.S. Events: January 1 - Same-sex marriage becomes legal in Maryland.
January 2 - President Barack Obama signs a bill that averts the "fiscal cliff."
January 21 - President Barack Obama is inaugurated for a second term. Obama was sworn-in to office the previous day, but because the date fell on a Sunday, the public festivities were postponed one day.
February 1 - John Kerry is sworn in as Secretary of State.
February 12 - President Barack Obama gives his State of the Union address.
March 1 - Forced cuts to the federal budget, also known as sequestration, kick in.
April 15 - Twin bombs at the finish line of the Boston marathon kill three people and injure more than 250.
April 17 - An explosion at a fertilizer plant in West, Texas kills 15 people.
April 19 - Boston Marathon bombing suspects Tamerlan and Dzhokhar Tsarnaev are involved in a confrontation with police. Tamerlan is killed and Dzhokhar escapes. After an all day manhunt, Dzhokhar is captured by police.
May 2 - Maryland governor Martin O'Malley signs a law repealing the state's death penalty. The law takes effect October 1.
May 6 - Three young women and a six-year-old girl are rescued from a house in Cleveland, Ohio. The three women had been held captive in the house by Ariel Castro for between nine and 11 years and endured rape and brutal physical abuse.
May 8 - Jodi Arias is found guilty of the 2008 murder of ex-boyfriend Travis Alexander.
May 20 - An EF5 tornado hits Moore, Oklahoma and surrounding areas. There are 25 confirmed fatalities.
June 9 - The Guardian and Washington Post disclose former Booz Allen contract employee Edward Snowden as their source for the intelligence related information recently published. Both published stories revealing the existence of PRISM, a program they say allows the NSA to extract the details of customer activities -- including "audio and video chats, photographs, e-mails, documents" and other materials -- from computers at Microsoft, Google, Apple and other Internet companies.
June 26 - The Supreme Court rejects parts of the Defense of Marriage Act (DOMA) in a 5-4 decision, dismissing an appeal over same-sex marriage on jurisdictional grounds and ruling same-sex spouses legally married in a state may receive federal benefits. It also rules that private parties do not have standing to defend California's voter-approved ballot measure barring gay and lesbian couples from state-sanctioned wedlock. The ruling clears the way for same-sex marriages in California to resume.
June 21 - The U.S. government charges fugitive leaker Edward Snowden with espionage and theft of government property.
June 30 - Nineteen elite firefighters are killed in a wildfire in Arizona.
July 1 - Same-sex marriage becomes legal in Delaware.
July 13 - George Zimmerman is found not guilty in the 2012 shooting death of Trayvon Martin.
July 30 - Pfc. Bradley Manning, on trial for leaking military information to the WikiLeaks website, is acquitted of aiding the enemy, but found guilty on 20 other counts, including violations of the Espionage Act. In August, he is sentenced to 35 years in prison.
August 1 - Cleveland kidnappings suspect Ariel Castro pleads guilty to the charges against him and is sentenced to life in prison plus 1,000 years. Just over one month later, he commits suicide in his prison cell.
August 1 - Same-sex marriage becomes legal in Rhode Island and Minnesota.
August 12 - Gangster James "Whitey" Bulger is convicted of multiple counts of racketeering.
August 17 - A wildfire breaks out at Yosemite National Park. The blaze, known as the Rim Fire, is one of the largest wildfires in California's history.