I just read some of this poem out of curiosity because I saw it referenced somewhere, and I’m still baffled about the accent and/or regional dialect represented in that poem. “Nen”, “ist”, and “uz” are all words that appear multiple times in the poem, and I thought I would understand them better after hearing them read aloud, but I don’t. Is that meant to be a southern accent, or maybe a dead north eastern dialect? Don’t get me wrong. I’m not complaining, but it’s interesting that this poem is a lot stranger to modern readers than he could have ever predicted.
I am no expert, but I think the dialect is rural central/southern Indiana from the late 19th to 20th century, judging from where the poet lived. Being from Indiana all my life, it rings true to me.
Since the poem is a written work, rather than an oral work, any supposed accent is a linguist choice made by the author to simulate the spoken word, and in this charming poem the language of children. 'Wuz' = "was". 'ist' = seems a hybrid of verbs including "is", "are", "I am", and "does", An' nen = "and then" (emphasis on the 'N' sound) , The dropping of first and last consonants is a very common practice in American English, and not necessarily a practice unique to Indiana regional dialect. Their are wide regional changes in vowel pronunciation, but that wide variation is in itself a very American English practice. Vowels are highly variable, but consonants are relatively constant in American English. Dialects are fascinating, a form of language, meaning, and nuance within a language.