Two Black Panther crew members made Oscar history by becoming the first black winners in their categories.
Ruth Carter scooped the costume design trophy, and Hannah Beachler shared the production design prize with Jay Hart.
"This has been a long time coming," Carter said in her speech. "Marvel may have created the first black superhero but through costume design we turned him into an African king."
Fellow Oscar winner Halle Berry was one of the first to congratulate her.
Carter's other films include Amistad, Malcolm X and Selma.
Meanwhile, Beachler - who has previously worked on Moonlight, Creed and Beyonce's Lemonade - paid tribute to Black Panther director Ryan Coogler.
"I stand here stronger than I was yesterday," she told the ceremony.
"I stand here with agency and self-worth because of Ryan Coogler, who not only made me a better designer, a better storyteller, a better person.
"I stand here because of this man who gave me a different perspective of life, who offered me a safe space, who's patient and gave me air, humanity and brotherhood.
"Thank you Ryan I love you."
Hannah Beachler was sweeping floors of a Lifetime movie. After walking onto sets across New Orleans, her chance came with Fruitvale Station. Then...Creed, Moonlight and Beyoncé’s Lemonade," before creating the world of Wakanda in Black Panther. Anything is possible. #Oscar2019 pic.twitter.com/yMh14NiGc6— DMoe (@dereyckM) February 25, 2019