The devastation caused by the 7.0 magnitude earthquake only adds to Haiti's decades of trouble and turmoil.
In January 1991, President Jean-Bertrand Aristide took office after winning Haiti's first democratic election in a landslide, only to be ousted in a military coup the following September.
Mr. Aristide returned to power in October 1994, after U.S. President Bill Clinton ordered thousands of U.S. Marines to the island nation to restore democracy.
A little more than a year later, former Prime Minister Rene Preval became Haiti's next president, followed again by Mr. Aristide in November 2000, amid allegations of election irregularities.
Mr. Aristide fled Haiti in February 2004, during a public rebellion. He is now offering to return from exile to help to rebuild his country.
Mr. Preval again won Haiti's presidency in 2006, after an internationally-brokered deal over disputed results.
In April 2008, Haitian lawmakers voted to dismiss Prime Minister Jacques Edouard Alexis following riots over escalating food prices.
Adding to the political turmoil, a string of natural disasters:
In September 2004, floods in the wake of Tropical Storm Jeanne killed nearly 3,000 people.
In 2008, four tropical storms and hurricanes killed more than 800 people and left some one million more homeless.
In November of the same year, a school outside Port-au-Prince collapsed, killing 95. Blame centered on shoddy construction.
Haiti's Ambassador to the United States, Raymond Joseph, says Haiti's troubled past has forged a spirit of perseverance.
"I expect the Haitian people to pull together," he said. "Those abroad who have been helping the country with funds will have to go deeper into their pockets, and those in the country to pull together in unity, we'll do it again."
But attitude is not enough. Hundreds of thousands of Haitians are in dire need of food, water and medicine. And the U.N. is appealing to the international community for $550 million to meet those needs.