Image copyright Getty Images

Delegates at the Democratic National Convention are poised to make history, formally nominating Hillary Clinton for president.

Mrs Clinton will become the first woman to lead a major party ticket in the US.

Delegations from all 50 states began reading their votes on the convention floor in Philadelphia.

Bernie Sanders, a primary race rival, is expected to deliver the deciding votes for Mrs Clinton's nomination as a show of party unity.

Sanders supporters disrupted the first day of the convention, often booing and jeering pro-Clinton speakers.

Tensions boiled over this week after leaked emails showed supposedly neutral Democratic Party officials were biased against Mr Sanders.

Both the Sanders and Clinton campaigns have been working to ease tensions and quieten the protests inside the convention hall.

The disruptions mostly subsided midway through Monday night's programme as big names like Mr Sanders, Massachusetts Senator Elizabeth Warren and First Lady Michelle Obama aggressively backed Mrs Clinton's candidacy.

Media playback is unsupported on your device Media caption Michelle Obama urged the Democrats to unite behind Hillary Clinton

Image copyright Getty Images Image caption Vice-President Joe Biden will speak later in the week

Visiting the convention floor on Tuesday, Vice-President Joe Biden dismissed the notion that Sanders supporters would vote for Republican nominee Donald Trump.

"Show a little a class. Let them vent a little while," Mr Biden said of the protesting delegates.

On Tuesday, former President Bill Clinton will headline the night's speakers, making the case for why his wife should take his old job.

Mr Clinton is seen an able booster for other Democrats, including President Barack Obama but has struggled to effectively promote his wife.

The rest of the programme will focus on race and justice, topics that dominated last week's Republican National Convention in Cleveland.

Sybrina Fulton, whose son Trayvon Martin helped inspire the Black Lives Matter movement, will be among the speakers.

Image copyright Getty Images Image caption Former President Bill Clinton will headline Tuesday night's speakers

The Democratic convention - all you need to know

Media playback is unsupported on your device Media caption What's the point of a party convention anyway?

1. What is the point? At a convention, each party formally nominates its candidates for president and vice-president, and the party unveils its party platform, or manifesto.

2. Who is there? There are about 5,000 delegates attending, selected at state and congressional district conventions, and representing each US state and territory. Plus about 15,000 journalists and tens of thousands of other party grandees, lawmakers and guests.

3. What is the schedule?