WASHINGTON (AFP) - Democratic candidates in the US states of Delaware and Vermont made history on Tuesday (Nov 3) when they became the first openly transgender legislators in their states.

Ms Sarah McBride, 30, became Delaware's first trans senator, taking 86 per cent of the vote in the state's first Senate district.

She is also the first openly trans state senator in the United States and the highest-ranking trans official in the country.

"We did it. We won the general election. Thank you, thank you, thank you," she tweeted on Tuesday night (Nov 3).

"I hope tonight shows an LGBTQ kid that our democracy is big enough for them, too."

Further north in Vermont, Ms Taylor Small, 26, became the state's first transgender representative, taking 43 per cent and 41 per cent of the vote in her two districts.

"5th trans legislator in the nation!" she tweeted.

Their wins come just a few years after Democrat Danica Roem became the first openly trans lawmaker in the US.

Ms Roem was elected to Virginia's state assembly in 2017.

In 2018, Vermont Democrat Christine Hallquist became the first openly transgender person nominated for governor by a major party in the United States.

The Victory Fund, a political action committee focused on increasing the number of openly LGBTQ elected officials in the US, congratulated Ms Small on Twitter, writing, "History made!"

The group also congratulated Ms McBride. In a statement posted online, Fund chief Annise Parker called Ms McBride's victory "a powerful reminder that voters are increasingly rejecting the politics of bigotry in favour of candidates who stand for fairness and equality".

According to the Victory Fund, there are currently four openly trans people serving in state legislatures.

For live updates and results, follow our US election live coverage.