Coverage of the Democratic Party Convention here
Watch Hillary Rodham Clinton's speech from last night here
Barack Obama is set to be nominated later this evening as the Democrats' presidential candidate.
Hillary Clinton released her delegates at the Democratic National Convention, freeing them to back Mr Obama.
She spoke to a crowd of about 3,000 people, including the nearly 2,000 delegates she won in the nomination fight with Mr Obama.
'This has been a joy. We didn't make it, but boy did we have a good time trying,' she said.
The crowd roared 'No' when she told them that she was releasing them as her delegates.
'We will leave Denver united. My goal is that we win in November,' she said.
Delegates prepared to lay the mantle of leadership on Mr Obama during afternoon events in which his name was to be placed into nomination.
Mr Obama was arriving in Denver to prepare for his acceptance speech tomorrow to a crowd of about 80,000 people at the Denver Broncos' pro football stadium.
Speaking at a veterans' round-table in Billings, Montana, Mr Obama said,'We've had a great convention so far'.
'We've had two powerful women speak back-to-back on each night, Michelle Obama and Hillary Clinton,' he said.
The Clintons remained a central point of focus at the four-day convention.
Tonight former President Bill Clinton gets the chance to pick up where Hillary Clinton left off - provide a ringing endorsement of Mr Obama's candidacy and criticize the Republican candidate, John McCain.
Senator Joe Biden of Delaware will be placed in nomination for vice president later this evening and will address the convention in the biggest speech in his political career that has spanned more than three decades.
Mr Biden is expected to play the role of 'attack dog' against Republican candidate John McCain, who has moved slightly ahead in some polls following weeks of Republican pounding of Mr Obama.
Some Democrats have also ripped into Mr Obama for picking Biden as his running mate rather that Mrs Clinton.
Republicans, who have set up an outpost in Denver, have been trying to exploit any signs of Democratic division.
While conceding that Clinton made a strong speech, they reiterated the main thrust of their attack on Mr Obama: that the first-term senator is unprepared to be president.
Last night, Mrs Clinton has urged the US Democratic Party to unite 'with a single purpose' to elect Barack Obama.
The New York senator was introduced in Denver last night by her daughter, Chelsea, while former US president Bill Clinton watched from the audience.
'Barack Obama is my candidate and he must be our president,' she said.
Delegates from across the US held 'Hillary', 'Obama' and 'unity' signs while Mrs Clinton thanked her supporters, her champions and her 'sisterhood of the travelling pantsuits'.
At the Pepsi Centre in Denver she reiterated her support for Mr Obama after listing the reasons why she ran for president.
Mrs Clinton said progress in the US would be impossible if 'we don't fight to put a Democrat in the White House'.
She said Mr Obama would end the war in Iraq responsibly, bring US troops home and restore US relations around the world.
The former First Lady also praised vice presidential candidate Joe Biden and Mr Obama's wife Michelle.
She slammed Republican Party candidate John McCain saying that it is appropriate that he would be in the twin cities of St Paul and Minneapolis with US President George W Bush next week because she said 'these days they're awfully hard to tell apart'.
In advance of her speech, Mrs Clinton had urged her supporters to help her put Barack Obama in the White House.
'I ask all of you who worked so hard for me, who knocked on doors and made those phone calls, who got in arguments from time to time ... to work as hard for Barack Obama as you did for me,' Senator Clinton told a luncheon crowd of about 2,500 who also heard from Mr Obama's wife, Michelle.
'Let's work our hearts out to elect Barack Obama and Joe Biden our next president and vice president,' she said.
The second day of the convention focused on economic themes and began to discuss Mr Obama's plans to aid lower and middle-class voters suffering in a faltering US economy, which polls show is the top issue in the final months of President Bush's term.
The convention's keynote speaker, filling the role that shot Mr Obama to political fame at the Democratic Convention in Boston in 2004, was former Virginia Governor Mark Warner.
The convention will finish Thursday evening with an in-person appearance from Mr Obama.
Look at photos from the convention
Read some of the key speeches from the convention
