boots and saddles

(Military) a bugle call formerly used in the US Cavalry to summon soldiers to mount

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

References in classic literature ?

and on she went, and cleared the last hurdle solitary and alone, the army letting loose the grand yell, and she skipped from the horse the same as if he had been standing still, and made her bow, and everybody crowded around to congratulate, and they gave her the bugle, and she put it to her lips and blew 'boots and saddles' to see how it would go, and BB was as proud as you can't think!