It beat off fierce competition from "Everything Is Awesome" (The Lego Movie), "Grateful" (Beyond the Lights), "Lost Stars" (Begin Again) and "I'm Not Gonna Miss You" (Glen Campbell: I'll Be Me).

In his acceptance speech, Legend said: "We wrote this song for a film that was based on events that were 50 years ago, but we say that Selma is now because the struggle for justice is right now. We live in the most incarcerated country in the world. There are more black men under correctional control today than were under slavery in 1850. When people are marching with our song, we want to tell you, 'We are with you. We see you. We love you. And march on.'"

In the Best Original Score category, Alexandre Desplat won out over favourite Jóhann Jóhannsson (The Theory Of Everything; read our in-depth guide to the score with the nominee here), for The Grand Budapest Hotel, one of two films he was nominated for - the other being The Imitation Game.

Check out the Academy Award-winning song below.