The United States Congress has overwhelmingly passed a bill to add a federal holiday to the calendar marking Juneteenth - the end of slavery in the nation.

The House of Representatives backed the legislation by 415-14, a day after it was unanimously approved by the Senate.

It is the first new federal holiday since Martin Luther King Junior Day was established in 1983.

Juneteenth marks the day on 19 June 1865 when enslaved black people in Texas learned they had been freed.

The measure now heads to the White House to be enacted into law.