Hold on there, Cal. You got some of yer calc-a-lations wrong.
Manhattan’s N-to-S blocks run twenty to the mile, not six. That makes CP a hair over 2.5 miles long. Eyeballing a scale map, it looks a bit over a half mile wide. (E-W blocks vary in length, so guestimating is all I’m gonna do for that dimension).
Anyway, you can get the rough square-mileage from that; meanwhile the NYC Encyclopedia sez it’s 843 acres.