When Emily Dickinson (born on this day in 1830) wrote her thousands of famous poems, she largely intentionally eschewed publication. That means there’s a treasure trove of fascinating information to be gleaned from both her manuscripts and the interpretations and publication of her poem in the ensuing years.

And then there are those dashes. Dickinson’s frequent use of the dash has been interpreted on dozens of symbolic and practical levels. They were musical notes! Pause indicators! Signifiers of female negativity punctuating the male space of the page!

OK, I made the last one up, but it’s not far from some of the interesting theories that have been floated about Amherst’s most famous genius shut-in.

In honor of Emily Dickinson’s birthday, here are six interesting facts about her writing process:

1. Many of her poems have multiple “variants.” She put little crosses which essentially served as asterisks on her pages, followed by corresponding footnotes, indicating many alternate word choices for each poem, so that none was ever “finished” or had an official version.

2. Her famous dashes, as written, weren’t uniform in shape or size. Some were longer than others. Some went upwards, some went downwards. Did this mean anything? People are still trying to figure it out.

3. Most people know that Dickinson’s spelling and punctuation were initially cleaned up and regularized when her poems were “discovered” and published but so was her language. Words were changed and censored, and the order of the poems in her “fascicles” was re-arranged.

4. She only published a handful of them in her lifetime, but wrote 3,507 known poems, some in letter and fragment form.

5. A contemporary critic, Thomas Wentworth Higginson, recognized her as a genius but also told her not to publish.

He ultimately became her only critic and literary mentor. In their first correspondence, she asked him if her poems were “alive” and if they “breathed.” He called her a “wholly new and original poetic genius.” He then immediately advised her against publication. Most likely, Higginson felt that she was unclassifiable within the poetic establishment of the day; departing from traditional forms as well as conventions of language and meter, her poems would have seemed odd, even unacceptable, to her contemporary audience. Even though he failed her as a critic and colleague—telling her not to publish, never offering any real encouragement—she was pleased that he read her poems, and credited her audience of one with “saving her life.”

6. Dickinson didn’t just write in notebooks or paper. She wrote on envelopes, opening them, closing them, and cutting them so the shape of the paper would be in conversation with the form and meaning of the poem.

Jen Bervin, a contemporary poet and artist, has been working to discern and present the meaning and symbolism of Dickinson’s work as it actually stood on the manuscript page. She explains:

Even in the most trusted scholarly editions, editors have restructured Dickinson’s poems for print in opposition to the manuscripts, consistently overriding her line breaks, systematically deconstructing (or in reading editions, omitting) her formal construction of variant words and punctuation. Without manuscripts present, the reader cannot know how those editorial omissions and decisions have affected meaning. Dickinson’s manuscripts themselves, and the forms and experiments borne out in them, are the most authentic register of her intentions.

Bervin has, among other Dickinson-related projects, worked to present facsimiles of the original manuscripts to readers.

See some of Bervin’s work recreating Dickinson’s “envelope poems” at the Poetry Foundation.