I am reading The Coalwood Way, by Homer Hickam, which is autobiographical, set in Coalwood WV, in 1960.

His mother uses I swan! --instead of i swear i guess.

the book is great, (crossing thread, now, since i posted here, not in Misc.) -- there are other words and expressions that are not ones i would use, but I swan ! is one i have never heard..

is this a southern expression, or one specific to Coalwood, WV