Election Day has arrived in the United States with millions of Americans going to the polls to vote for the country’s next president, along with landmark public referendums on equal marriage taking place in four different states.

The polls are now open in New York, Ohio, Florida, and Massachusetts – the state which Republican challenger Mitt Romney previously governed until 2007.

President Obama appears to have the narrowest of leads over Mr Romney in a number of critical swing states.

The differences between the two men on LGBT rights are substantial.

During his past four years in office, President Obama has presided over a number of LGBT achievements, such as overturning Don’t Ask, Don’t Tell (the ban on openly gay soldiers), abandoning federal approval of the Defence of Marriage Act, extending hospital visitation and care rights to gay spouses, and appointing a record number of gay officials.

In contrast, Mitt Romney, who in 2002 said: “All citizens deserve equal rights, regardless of their sexual orientation,” is opposed to same-sex marriage and civil unions, supports a constitutional amendment to outlaw equal marriage, and has been keen to limit the legal entitlements of same-sex parents. Mr Romney has also made a promise: to only appoint Supreme Court judges who oppose equal marriage.

In a possible sign of a tight race ahead, the first voting on Tuesday saw both candidates receive five votes each in the tiny town of Dixville Notch, New Hampshire.

The next 24 hours will be a significant moment for LGBT rights in America. There are referendums on equal marriage in Washington, Maryland and Maine.

In Maryland and the state of Washington, voters will decide on whether to uphold or reverse moves to permit same-sex marriage.

Meanwhile, in Minnesota, residents will vote on a measure that would ban same-sex marriage, while allowing civil unions.

Maine is voting on the issue without a previous verdict taken by the state’s legislature or by voters.

According to the website Politico, there appears to be a majority of support for equal marriage in Maine and Maryland – but it remains a tight race in both states.