Green’s Dictionary of Slang

(US) proud.

1844		‘Jonathan Slick’ High Life in N.Y. I 47: The old woman began to brag about Samuel, for she’s felt mighty crank about him ever since he had that great dinner give to him.
1856		Mrs Stowe Dred I 320: You strong electioners think you’s among the elect! [...] You wouldn’t be so crank about it, if you didn’t!
1860		J.G. Holland Miss Gilbert’s Career (1870) 262: I tell you we feel pretty crank about having a book-writer in Crampton.