When you say composition and publication, I'm supposing you mean structure and unique circumstances surrounding the poem. "To Marguerite--Continued" is one of Arnold's early poems (before his marriage in 1851) written during his Switzerland visit, 1848 to 1849. There has been a long controversy over the true existence of Marguerite but recent scholarship has found Arnold letters that refer to a real person, and a name has been attributed to her (though not without continuing controversy), that of Marguerite Claude. Arnold chronicles the course of their ill-fated love in the series of lyric poems collected as Switzerland.
Who order'd, that their longing's fire
Should be, as soon as kindled, cool'd?
And bade betwixt their shores to be
The unplumb'd, salt, estranging sea.
First published in Empedocles on Etna and Other Poems in 1852, Arnold gave the poem more than one title. The 1852 title was the complicated "To Marguerite, In Returning a Volume of the Letters of Ortis." The 1853 title by which it was included in Switzerland was "To Marguerite." The 1857 title for the Marguerite poem was "Isolation," but the 1869 title was the final one as we have it today: "To Marguerite--Continued." It seems safe to say this poem drew a lot of Arnold's attention over the decades (1848 to 1869).
A Victorian period poem in four stanzas, each stanza has an alternating rhyme for four lines with a rhyming couplet at the end of each sestet stanza. Each sestet has different rhymes but each follows the ababcc scheme pattern established in the first stanza:
Yes! in the sea of life enisled, a
With echoing straits between us thrown, b
Dotting the shoreless watery wild, a
We mortal millions live alone. b
The islands feel the enclasping flow, c
And then their endless bounds they know. c