“He had worked for an entire year to make a dream come true, and that dream, minute by minute, was becoming less important. Maybe cause that wasn't really his dream.”

"Where Love Is, God Is" (1885), also translated as "Where Love is, There God is Also" - (full text online)
Context: Martin's soul grew very very glad. He crossed himself put on his spectacles, and began reading the Gospel just where it had opened; and at the top of the page he read: I was an hungered, and ye gave me meat; I was thirsty, and ye gave me drink; I was a stranger, and ye took me in. And at the bottom of the page he read: Inasmuch as ye did it unto one of these my brethren even these least, ye did it unto me (Matt. xxv). And Martin understood that his dream had come true; and that the Saviour had really come to him that day, and he had welcomed him.

"Over the Rainbow" in The Wizard of Oz (1939) - Judy Garland version https://www.youtube.com/watch?v=PSZxmZmBfnU
Context: Somewhere over the rainbow,
Way up high
There's a land that I heard of
Once in a lullaby.
Somewhere over the rainbow
Skies are blue
And the dreams that you dare to dream
Really do come true.

Southern Accents
Lyrics, Southern Accents (1985)

(1945)

The Wheel on the School (1954)

Speech at MIT (1985), referring to his brother Bernard Vonnegut, and the choices available to scientists and the intelligent, to serve humanity, or to betray it, as published in Fates Worse Than Death (1991), Ch. 12
Various interviews
Context: My brother got his doctorate in 1938, I think. If he had gone to work in Germany after that, he would have been helping to make Hitler's dreams come true. If he had gone to work in Italy, he would have been helping to make Mussolini's dreams come true. If he had gone to work in Japan, he would have been helping to make Tojo's dreams come true. If he had gone to work in the Soviet Union, he would have been helping to make Stalin's dreams come true. He went to work for a bottle manufacturer in Butler, Pennsylvania, instead. It can make quite a difference not just to you but to humanity: the sort of boss you choose, whose dreams you help come true.
Hitler dreamed of killing Jews, Gypsies, Slavs, homosexuals, Communists, Jehovah's Witnesses, mental defectives, believers in democracy, and so on, in industrial quantities. It would have remained only a dream if it hadn't been for chemists as well educated as my brother, who supplied Hitler's executioners with the cyanide gas known as Zyklon B. It would have remained only a dream if architects and engineers as capable as my father and grandfather hadn't designed extermination camps — the fences, the towers, the barracks, the railroad sidings, and the gas chambers and crematoria — for maximum ease of operation and efficiency.

"Pat Carroll; Gertrude Stein was never a bore" (January 8, 1981)

Song lyrics, The Red Shoes (1993)
Context: Feel your hair come tumbling down
Feel your feet start kissing the ground
Feel your arms are opening out
And see your eyes are lifted to God
With no words, with no song
I'm gonna dance the dream
And make the dream come true…