We recently started working on a bridge project in this little town that I can't think of at the moment but the creek name is Negro creek. And locals tell me its still named that for a reason.An African American expert on black culture said that cracker was used in the slave days, by slaves, as a name for the overseer who "cracked the whip" to get them to work harder. It had nothing to do with a persons color as the overseer could have been black or white.
And according to my dad (born in 1894) there were several all black sundown towns in Oklahoma where whites were not allowed after sundown.