2008
5 November
Barack Obama makes history by becoming the first African American to win the US presidency.
With the promise of “hope and change”, he enters the White House as America is fighting wars in Iraq and Afghanistan. At home, the US faces the worst financial crisis since the Great Depression of the 1930s.
2009
22 January
The new president promises to close Guantánamo Bay, the contentious US facility in Cuba used to detain terror suspects, many of whom are held without charge. To this day, it remains open.
17 February
Obama signs a huge $787bn (£548bn) stimulus bill designed to save and create thousands of jobs to boost the beleaguered US economy.
18 February
A surge in violence in Afghanistan sees Obama pledge an extra 17,000 military personnel, doubling the US presence there. Days later he promises to end to the war in Iraq: “Let me say this as plainly as I can: by August 31, 2010, our combat mission in Iraq will end.”
31 March
Obama flies into London for the G20 summit where talks about the global financial crisis dominate. He meets the British prime minister, Gordon Brown, and other world leaders. The president and his wife also meet the Queen. Leaving the UK, Obama visits Turkey, where he says: “The United States is not, and will never be, at war with Islam.”
30 July
The president tries to act as peacemaker by holding a “beer summit” at the White House with a black Harvard professor arrested for alleged disorderly conduct outside his home in Massachusetts and the white police officer who took him in.
9 October
Obama wins the 2009 Nobel peace prize and says he is “surprised and deeply humbled”.
The Nobel committee says the award was made in honour of “his extraordinary efforts to strengthen international diplomacy and cooperation between peoples”.
28 October
Obama signs the Matthew Shepard and James Byrd Jr Hate Crimes Prevention Act, expanding hate-crime law to address attacks over gender, sexual orientation, gender identity and disability.
2010
23 March
Obama’s flagship healthcare reform bill, also known as Obamacare, is passed by Congress. Bitterly opposed by Republicans, the landmark policy, estimated to cost $940bn (£627bn), aims to bring near-universal health coverage to Americans.
8 April
Obama and Russian leader Dmitry Medvedev sign the New Strategic Arms Reduction Treaty (New Start). The new treaty is intended to cut US and Russian strategic nuclear warheads from 2,200 to 1,550 over seven years.
20 April
As the Deepwater Horizon oil rig explodes off Louisiana, leaving 11 crew members dead and threatening to cause a huge environmental catastrophe, Obama deals with what some call his “Katrina moment”.
28 November
The Guardian publishes details of 250,000 American diplomatic cables, some marked “secret” or “confidential”, from the WikiLeaks whistleblowing website. In response, the White House says: “President Obama supports responsible, accountable and open government at home and around the world, but this reckless and dangerous action runs counter to that goal.” The founder of WikiLeaks, Julian Assange, says the US authorities were afraid of being held to account.
18 December
The Arab Spring begins. Obama later pays tribute to the uprisings in the Middle East and North Africa as “a moment of opportunity” for change in the region.
22 December
Obama signs a landmark law, the Don’t Ask, Don’t Tell Repeal Act, that allows gay people to serve openly for the first time in the US armed forces.
2011
19 March
The UK, US and France attack Muammar Gaddafi’s forces in Libya to enforce a UN-mandated no-fly zone. The “worst mistake” of his presidency is how Obama described his lack of support to Libya after Gaddafi was deposed.
27 April
In the same month as Obama announces his bid for re-election, he also yields to “birthers” and Donald Trump, who insisted he publish his birth certificate, to quash rumours that he was born outside the US.
2 May
Osama bin Laden, the world’s most wanted man, is killed by US special forces in a night-time raid of his secret compound in Abbottabad, Pakistan. Obama and his top advisers watch a live feed of the mission from the White House Situation Room.
15 December
Obama formally declares that the Iraq war is over and that the US is to pull out. In a speech at Fort Bragg, North Carolina, the president is careful not to say the US won the nine-year conflict.
2012
26 February
The fatal shooting of Trayvon Martin, an unarmed black teenager, in Florida by an armed neighborhood-watch volunteer prompts Obama to say: “If I had a son, he’d look like Trayvon.” The man who shot Martin is found not guilty of second-degree murder and acquitted of manslaughter, a lesser charge. But some protesters claim Martin was only stopped because of racial profiling.
9 May
Obama becomes the first sitting US president to back the right of gay and lesbian couples to marry.
29 August
Obama takes part in a Reddit “Ask Me Anything” Q&A session on the popular news site. One of the questions he is asked is whom he would rather fight: “100 duck-sized horses or one horse-sized duck?”
6 September
The Democratic party convention in Charlotte backs Obama as nominee for the 2012 presidential race but some delegates express disappointment about his first term.
6 November
Obama’s popularity may have slipped but he wins re-election, beating Republican challenger Mitt Romney. In his victory speech, he says: “I have never been more hopeful about America. And I ask you to sustain that hope.”
14 December
Obama wipes away his tears when addressing the nation about the 20 children and six adults who died in a mass shooting at Sandy Hook elementary school in Newtown, Connecticut. Promising “meaningful action”, he also says: “As a country, we have been through this too many times.”
2013
2 January
A compromise bill pushed through by Obama prevents the US falling off the “fiscal cliff” – a set of scheduled tax rises and sharp spending cuts likely to trigger a new recession.
21 March
Warning about the use of chemical weapons, Obama tells Syria’s Assad regime that there is a “red line” that must not be crossed.
15 April
Three people are killed after two brothers plant homemade pressure cooker bombs near the finishing line of the Boston Marathon. One of the bombers is killed when cornered by police, the other captured and put on trial – he is found guilty and sentenced to death in 2015.
5 June
The Guardian publishes leaked documents from whistleblower Edward Snowden about the clandestine activities of the US National Security Agency, for whom he had previously worked. In what is regarded as one of the most significant leaks in American political history, Snowden has evidence that the NSA maintained a number of mass surveillance programmes over its own citizens, including accessing information stored by some of the country’s biggest technology companies. Responding, Obama says: “You can’t have 100% security, and also then have 100% privacy and zero inconvenience.”
25 June
Obama unveils the country’s first-ever climate change strategy, which includes cutting power plant emissions and protecting coastlines.
1 October
The first federal government shutdown in two decades begins after Congress fails to pass legislation lifting the “debt ceiling”.
10 December
At the Nelson Mandela memorial service in South Africa, Obama shakes hands with the Cuban leader, Raúl Castro, proving relations between the two countries have improved.
Obama’s decision to pose for a selfie with David Cameron and the Danish prime minister Helle Thorning-Schmidt later on was not particularly well received.
2014
28 February
The White House accuses Moscow of orchestrating a “military invasion and occupation” of the Crimea peninsula in southern Ukraine, potentially putting the Kremlin and the west on a collision course.
16 June
A rampant Isis-led insurgency prompts Obama to send approximately 275 armed personnel to Iraq to help put down possibly the worst threat to the country since US troops left in 2011. Within months, he also authorizes airstrikes against Isis positions in Syria.
9 August
Protesters chanting “black lives matter” clash with police in the St Louis suburb of Ferguson after Michael Brown, an unarmed black 18-year-old, is shot and killed by the police officer Darren Wilson.
15 October
Speaking about the death toll of Ebola victims climbing to 4,500 since an outbreak in west Africa, Obama says the US must respond much more aggressively to prepare at home and confront the outbreak abroad.
5 November
The Republicans take control of Congress following midterm elections, leaving Obama with a bigger headache if he is to pass new laws.
20 November
Obama says he will use executive powers to bypass Congress’s opposition to his controversial plan to allow four million undocumented US immigrants to apply for work permits.
28 December
Obama declares the “end of the combat mission in Afghanistan”.
2015
13 January
Obama is criticised for not attending a peace rally in Paris to remember 17 people who died in a wave of attacks that included the Charlie Hebdo offices.
2 March
The New York Times reveals that Hillary Clinton, when serving as Obama’s secretary of state, broke official rules by using a personal email instead of a government one for official correspondence. Clinton would continue to be dogged by the revelation.
14-24 July
The Obama administration succeeds in getting Iran to make drastic cuts to its nuclear programme in return for the lifting of sanctions. In the same month, Cuba and the United States restore diplomatic relations, ending over 50 years of hostility. Obama also travels to his paternal homeland of Kenya for the Global Entrepreneurship Summit in Nairobi.
28 October
Prince Harry meets Obama in the White House to promote next year’s Invictus Games for wounded service personnel.
30 November
Barack Obama hails the Paris climate change agreement as “a turning point for the world”. Months earlier he had announced his clean power action plan to get the US to curb carbon pollution.
2016
22 April
At a joint press conference with the prime minister, David Cameron, in London, Obama warns the British public that a vote to leave the EU could put the UK at the “back of the queue” when negotiating trade deals with the US.
27 May
Obama calls for a “world without nuclear weapons” during a visit to Hiroshima.
28 July
Obama gives a rousing speech at the Democratic convention in Philadelphia, willing Hillary Clinton to triumph over the “home-grown demagogue” Donald Trump.
28 September
Obama suffers the humiliation of having Congress override his veto for the first time. The president tried to block a law that allowed 9/11 families to sue Saudi Arabia for its alleged role in the September 11 attacks.
8 November
Donald Trump defeats Hillary Clinton in one of the biggest upsets in US political history. Trump will be sworn in as the 45th president of the United States next month. Both the House and Senate will remain under Republican control.
10 November
Obama, having congratulated Trump by telephone, then meets the president-elect at the Oval Office to discuss the transition of power between them. Obama had previously called Trump “unfit” for high office.
15 November
Obama sets off on a final international trip as president, landing first in Athens.
23 December
The US abstains from voting in a UN Security Council resolution that declares Israeli settlements in Palestinian territory illegal. Previously, the US could always be counted on to veto such a bill.
28 December
Obama designates two new national monuments, protecting over 150m acres of land, including sacred Native American sites, in Nevada and Utah. During Obama’s presidency, he has federally protected over 550m acres with his executive powers.
30 December
Obama places sanctions on Russia and expels 35 Russian diplomats from the US in retaliation for a cyber-attack against the Democratic National Conmittee during the 2016 election that according to US intelligence agencies was intended to help Trump win the election.
Additional reporting by Amber Jamieson
