Student or Learner
I don't understand what "drew upon" means here:
He (Martin Luther King) was about to sit down when gospel singer Mahalia Jackson called out, "Tell them about your dream, Martin! Tell them about your dream!" Encouraged by shouts from the audience, King drew upon some of his past talks, and the result became the landmark statement of civil rights in America - a dream of all people of all races and colours and backgrounds, sharing in an America marked by freedom and democracy.
To be honest, I thought "drew upon" means "remembered", but I didn't find that definition in the dictionary.
As a result, I have no idea what it means. Can you replace "drew upon" with one word?
Please, correct all my mistakes. I should know English perfectly and if you show me my mistakes I will achieve my dream a little bit faster. A lot of thanks.
Not a teacher nor a native speaker.