Background
"Little Orphant Annie" was written by the best-selling writer, James Whitcomb Riley. He was born in Indiana and known for his works appealing to a young, or child, audience. The poem was first published in the Indianapolis Journal on November 15, 1885 titled as "The Elf Child."

Structure
The poem is composed of four stanzas, each one with twelve lines. The final four lines of each stanza were stylized as resembling steps, or stairs, likely to increase the dramatic effect of the words "Elf you don’t watch out." It is written in what is known as the Hoosier dialect of Indiana, sometimes making some of the words difficult to understand or uncommon in plain, modern English. It follows an AABBCCDD rhyme scheme (changes every stanza), with the DD being rhymed between the 7th and 12th lines– the final five lines of each stanza are like one line broken up for effect. It is also of note that the poem’s structures and sounds are much better appreciated when read aloud.

Analysis
Little Orphant Annie’s come to our house to stay,

Annie, an orphan, has come to the house of the speaker. The first line indicates she is there permanently rather than just a short-term guest.

An’ wash the cups an’ saucers up, an’ brush the crumbs away,
An’ shoo the chickens off the porch, an’ dust the hearth, an’ sweep,
An’ make the fire, an’ bake the bread, an’ earn her board-an’-keep;

Annie, however, does not seem to be there as a part of the family or new child or sibling. She does much housework throughout the day. In the fourth line of the first stanza, it is clarified she must do the housework to earn her keep.

An’ all us other childern, when the supper-things is done,
We set around the kitchen fire an’ has the mostest fun
A-list’nin’ to the witch-tales ‘at Annie tells about,
An’ the Gobble-uns ‘at gits you
Ef you
Don’t
Watch
Out!

Once the housework is done and Annie has completed her chores, she provides some delightful entertainment for the other children of the house. The relationship between Annie and the other children seems like a good one given they have the "mostest fun" listening to her stories. The last five lines of the stanza indicate the stories she tells can be scary but still enjoyable.

Wunst they wuz a little boy wouldn’t say his prayers, —

In the first line of the second stanza is a prime example of how some words written in dialect may difficult to understand. "Wunst they wuz a little boy" would now be written as "Once there was a little boy" in common, modern English. The second stanza serves to demonstrate one of the stories Annie would share with the other children of the house. It starts off with a little boy who would not say his prayers, something that was considered naughty.

An’ when he went to bed at night, away up-stairs,
His Mammy heerd him holler, an’ his Daddy heerd him bawl,
An’ when they turn’t the kivvers down, he wuzn’t there at all!

Lines 2-4 of the second stanza begin to show the consequences of the little boy not saying his prayers. Once he is upstairs, out of sight from his mother and father, they hear him hollering and crying. Unfortunately, when they go into his room he is nowhere to be found. He is not even under his "kivvers," which in this case are "covers."

An’ they seeked him in the rafter-room, an’ cubby-hole, an’ press,
An’ seeked him up the chimbly-flue, an’ ever’-wheres, I guess;

In these two lines, there are many words used to describe and name places that may not be common or known. What can be easily deduced, however, is that the boy’s parents looked everywhere for him but could not find him.

But all they ever found wuz thist his pants an’ roundabout: —
An’ the Gobble-uns ‘ll git you
Ef you
Don’t
Watch
Out!

The second stanza ends just like the first¬– with a warning about goblins that will take the children, presumably, if they don’t watch out. Based on the little boy refusing to do his prayers, it is safe to assume he was taken for disobedience.

An’ one time a little girl ‘ud allus laugh an’ grin,
An’ make fun of ever’ one, an’ all her blood-an’-kin;

The first two lines of the third stanza can be, like other lines of the poem, difficult to understand. Broken down and simply put, they tell of a little girl who would laugh and tease everyone, including her family members. Already a pattern appears in which naughty children are taken by goblins, indicating Annie was telling stories to the other children for entertainment and to teach them valuable lessons.

An’ wunst, when they was “company,” an’ ole folks wuz there,
She mocked ’em an’ shocked ’em, an’ said she didn’t care!
In the next two lines the little girl even mocked elderly people. This shows just how naughty and disrespectful she is.

An’ thist as she kicked her heels, an’ turn’t to run an’ hide,
They wuz two great big Black Things a-standin’ by her side,
An’ they snatched her through the ceilin’ ‘fore she knowed what she’s about!

The three lines before the warning of the goblins show them actually taking her, if the "Black Things" are taken to be them.

An’ the Gobble-uns ‘ll git you
Ef you
Don’t
Watch
Out!

Once again the same warning about the goblins is uttered. Like the two stanzas beforehand, the final lines are spaced out.

An’ little Orphant Annie says, when the blaze is blue,
An’ the lamp-wick sputters, an’ the wind goes woo-oo!
An’ you hear the crickets quit, an’ the moon is gray,
An’ the lightnin’-bugs in dew is all squenched away, —

The first four lines of the final stanza are very descriptive of surroundings, many in a typical fashion of spookiness. This is very fitting for Annie to tell the children as a way to end her stories.

You better mind yer parunts, an’ yer teachurs fond an’ dear,
An’ churish them ‘at loves you, an’ dry the orphant’s tear,
An’ he’p the pore an’ needy ones ‘at clusters all about,

Coming full circle with teaching the children to be good and kind, she directly mentions listening to parents, being respectful, and loving those around them. She also talks of helping those in need, including orphans, something that point to Annie herself.

Er the Gobble-uns ‘ll git you
Ef you
Don’t
Watch
Out!

She ends with the final warning to be sure the children understand– be good, and you will be safe.

Summary
The poem tells of Annie, an orphan, who has come to live at a house where other children reside. She does many of the household chores but in addition to that she also tells stories to the kids. These stories are not only entertaining and spooky fun, they also are intended to teach the children a valuable lesson. At the end of every stanza the, the drawn out warning of the goblins taking children who "don’t watch out" is repeated. This means they need to be careful of their actions and not be naughty so as to not be taken by the scary goblins as a consequence.

Theme
The theme of the poem is to have strong moral values, like Annie does, in order to be safe and live well.

References
– allpoetry.com/Little-Orphant-Annie
– www.poetryfoundation.org/bio/james-whitcomb-riley