From winding down the war in Iraq to limiting lobbyists, Obama has made some progress. The president has faced political reality, however, by accepting, sometimes grudgingly, compromises that leave him exposed to criticism.
Promises that have proven difficult include pledges not to raise taxes, to curb the practice in Congress of setting aside expensive pet projects for individual members and to shut down the Guantanamo Bay detention facility in Cuba by the end of his first year.
"We are moving systematically to bring about change, but change is hard," Obama told a town hall crowd in California. "Change doesn't happen overnight."
That was in March. During his two-year campaign, Obama thrilled massive crowds with soaring speeches, often railing against an Iraq war that now is seldom mentioned.
His presidential comments now are often sober updates on issues like terror and the economy, a top priority now that emerged as a major issue only in the campaign's final weeks.
Obama's campaign ambition has been diluted with a pragmatism that has been the hallmark of Year One - without much of the progress he had hoped.
A look at some of the promises:
THE ECONOMY, TAXES AND DEFICITS Obama inherited an economy in severe distress that has since shown marked improvement. With the crisis developing so close to last year's election, it was not the focus of his earlier campaign promises.
But Obama managed to craft his main anti-recession measure to deal with one of the top political commitments. He campaigned on a pledge to provide a $US1000 ($NZ1346) tax credit to 95 percent of all working families, and almost delivered.
The $US787 billion stimulus bill included an $US800 tax credit for couples making up to $US150,000, and a declining credit for those making up to $US190,000.
The Tax Policy Centre estimates that 90 percent of taxpayers qualified for a tax cut under the stimulus package.
In a Dover, New Hampshire, campaign stop, Obama pledged that "no family making less than $US250,000 will see their taxes increase - not your income taxes, not your payroll taxes, not your capital gains taxes, not any of your taxes."
True, unless you're a smoker. Obama, himself an occasional smoker, signed into law a 159 percent increase in the federal tax on a pack of cigarettes. Other tobacco products were hit with similar or much steeper increases to help pay for a children's health initiative, enabling him to keep another promise to make sure all kids have health insurance.
Obama also promised to cut the federal budget deficit by more than half in his first term. That now appears unlikely, given the spending on the stimulus and the billions of dollars spent on bank and auto company bailouts.
The 2009 federal budget deficit hit a record $US1.42 trillion, and the red ink in the first two months of the 2010 budget year, which ends September 30, was nearly 6 percent higher than the corresponding period in 2009.
FOREIGN POLICY As a candidate, Obama bragged of his early opposition to the Iraq war and pledged to pull all US combat troops out within 16 months.
As president, he pushed that deadline back two months, to August 2010. Even then, he will leave 35,000 to 50,000 military personnel in Iraq through 2011 to train, equip and advise Iraqi security forces and to help in counterterror missions.
As a candidate, he vowed to prosecute the war against al-Qaida in Afghanistan, arguing that Iraq had distracted the United States from its anti-terror priorities.
By the end of his first year, he had retooled the Afghan war strategy, replaced the US commander there, doubled the number of US troops in the country and ordered another 30,000 there by the middle of this year.
He also promised to "end the use of torture without exception" in US anti-terror campaigns and to close the Guantanamo Bay jail, which he called "a recruiting tool for our enemies."
He signed an executive order outlawing torture, cruelty and degrading treatment of prisoners. A companion order closing the Guantanamo prison has proved more challenging. Congress refused to pay for the transfer of any Guantanamo detainees to US prisons, and foreign countries are reluctant to accept them.
Obama ordered the purchase of an Illinois prison to house up to 100 Guantanamo detainees. Still, Guantanamo cannot be closed until the disposition of more than 200 remaining detainees is resolved.
A failed attempt at bombing a Detroit-bound airliner on Christmas has made that more difficult.
Obama also campaigned to restore US prestige abroad by engaging allies and adversaries alike, a direct swipe at George W. Bush, his predecessor. Now, he is finding that rhetoric tough to live up to.
He vowed to use "tough, direct diplomacy" to keep Iran from obtaining nuclear weapons. Once in office, he offered dialogue to Tehran, made direct appeals to the Iranian people and included Iran in multinational discussions, while insisting that Iran not be permitted to develop nuclear weapons.
The power centres in Tehran have largely shrugged, and Obama so far has been unable to unite a coalition of countries behind new economic sanctions intended to block Iran's development of nuclear weapons.
A solution for North Korea's nuclear programme also remains elusive. Its envoy to the United Nations said his nation is willing to conduct talks, but only after all sanctions against it are lifted.
TERRORISM On his 2008 campaign Web site, Obama declared, "We must redouble our efforts to determine if the measures implemented since 9/11 are adequately addressing the threats our nation continues to face from airplane-based terrorism," including screening all passengers against "a comprehensive terrorist watch list."
The verdict on that promise came last month, when an alleged terrorist known to authorities boarded an airliner bound for Detroit from overseas carrying explosives in his clothes.
Disaster was averted when he botched an attempt to ignite the bomb.
HEALTH CARE During his political run, Obama said he would increase the number of people covered by health insurance and pay for it by raising taxes on families making more than $250,000 a year and by taxing companies that do not offer coverage to employees.
Although lawmakers have moved toward the broad outline Obama promised, it remains unfinished. The House of Representatives and Senate have passed versions of the plan, but major differences remain.
And Obama's left flank is none too pleased with the compromises to this point, which have all but eliminated a government-run insurance option, which he promoted during the campaign.
Even the process has violated one campaign pledge. "We'll have the negotiations televised on C-SPAN, so that people can see who is making arguments on behalf of their constituents, and who are making arguments on behalf of the drug companies or the insurance companies," Obama said.
That has not happened. Instead, Democrats in Congress and the White House have made multibillion-dollar deals with hospitals and pharmaceutical companies in private.
C-SPAN asked to televise the negotiations between the House and Senate versions; the White House insists it has not seen the request.
