What is Juneteenth, observed each year on June 19 in US?

'Juneteenth', a combination of the words 'June' and 'nineteen', is celebrated annually on June 19 in the US to mark the emancipation of enslaved Black Americans. It commemorates the day in 1865 when Union soldiers arrived in Texas to inform residents that slavery had been abolished in US following the civil war. Juneteenth became a US federal holiday in 2021.