From a GameFAQs guide:

"Your replies

(a) Dude, the way that we have treated Native Americans is most non- triumphant!

(b) Excellent, dude! Cowboys and Indians?! Count me in!

(aa) Dude, remember the golden rule - be excellent to each other.

(ab) Dude, violence never pays.

(ac) I just do not think that we should treate Native Americans in this most bogus way.

(ba) Before I can enlist, good captainly dude, I must find ___!

(bb) Look dude, the way that I’ve been treated around here, I have little interest in fighting to defend these people.

(bc) I’d love to sign up, but ___ has my pen."

Looks like it was a dialogue option with a Marshal character.