- When black folks lived in slavery, who was it set the darkie free?
- Abraham.
- That's right, child. Abraham.

14 seconds sound clip from the Holiday Inn (1942) movie soundboard.

You can hear this line at 00:46:32 in the Blu-ray version of the movie.

Quote context

[...]

- Upon a February morn, a tiny baby boy was born: Abraham.

- When he growed up, this tiny babe, folks all called him Honest Abe. Abraham, Abraham.

- In 1860, he became the sixteenth president. And now he's in the hall of fame, a most respected gent.

- That's why we celebrate this blessed February date.

- Abraham, Abraham.

- When black folks lived in slavery, who was it set the darkie free?

- Abraham.

- That's right, child. Abraham.

- When troubles come down from the shelf, who's heart was bigger than his-self? Abraham.

- Yeah, ma'am!

- Abraham.

- The country's going to the dogs, they shouted loud and strong, then from a cabin made out of logs, the right man came along

[...]