Green’s Dictionary of Slang

Dan O’Leary n.

In phrases

[US baseball player Daniel O'Leary (1856-1922)] do the Dan O’Leary (act/stunt) (v.)

(US) to walk .

1904		C. Connors Bowery Life [ebook] Let’s do de Dan O’Leary—walk, yer know—an’ blow in de car far fer er cupple uv mugs uv ale.
1915		Morn. Tulsa Dly World (OK) 13 June 19/1: Dan O’Leary act — To walk.
1923		Mixer & Server 32 27: the poor boob that thinks he can do the Dan O'Leary stunt and pass up the choo-choo cars from the Gulf to the Pacific has not been long enough in this man's country to know the difference between 'hot dawgs and sore dawgs.