Why did Samuel Barber write Adagio of Strings?

Samuel Barber composed the "Adagio for Strings" in 1936 as a string orchestration of the second movement of his string quartet, Op. 11. The piece is characterized by its profound emotional depth and has been interpreted as an expression of sorrow and introspection. Barber initially wrote it as a reflection on personal experiences, but its universal themes of loss and mourning have resonated widely, leading to its frequent use in various memorial contexts and films. The Adagio has since become one of Barber's most famous and enduring works.