What two things in John’s encounter with the school kids let them know that he is from over the Big Creek?

John's appearance:

“Ah think he musta come from over de Big Creek. ’Tain’t nothin' lak dat on dis side, the little tormenter went on. Then she looked right into his eyes and laughed. All the others laughed. John laughed too.

John's use of the word, Master:

The little girl snorted, “Marse Alf! Don’t y’all folkses over de creek know slavery time is over? ’Tain’t no mo’ Marse Alf, no Marse Charlie, nor Marse Tom neither. Folks whut wuz homed in slavery time go ’round callin’ dese white folks Marse but we been born since freedom. We calls ’em Mister. Dey don’t own nobody no mo’.”