Green’s Dictionary of Slang

1. a victory [which is ‘chalked up’].

1824

Pierce Egan’s Life in London 19 Dec. 381/1: This round was a chalk for O'Neal : he took the lead, kept it, and milled his opponent down.

2. a scar or scratch.

1840

Marryat Poor Jack 27: Messmate, as I have told you how I got this chalk, suppose you tell me in return how you got that nose of yours fixed so hard a starboard?