As with many other 19th-century novels, Onegin was written and published serially, with parts of each chapter often appearing in magazines before the first printing of each chapter.
Many changes, some small and some large, were made from the first appearance to the final edition during Pushkin's lifetime.
The following dates mostly come from Nabokov's study of the photographs of Pushkin's drafts that were available at the time, as well as other people's work on the subject.

The first stanza of chapter 1 was started on May 9, 1823, and except for three stanzas (XXXIII, XVIII, and XIX), the chapter was finished on October 22.
The remaining stanzas were completed and added to his notebook by the first week of October 1824.
Chapter 1 was first published as a whole in a booklet on February 16, 1825, with a foreword which suggests that Pushkin had no clear plan on how (or even whether) he would continue the novel.

Chapter 2 was started on October 22, 1823 (the date when most of chapter 1 had been finished), and finished by December 8, except for stanzas XL and XXXV, which were added sometime over the next three months.
The first separate edition of chapter 2 appeared on October 20, 1826.

Many events occurred which interrupted the writing of chapter 3.
In January 1824, Pushkin stopped work on Onegin to work on The Gypsies.
Except for XXV, stanzas I–XXXI were added on September 25, 1824.
Nabokov guesses that Tatyana's Letter was written in Odessa between February 8 and May 31, 1824.
Pushkin incurred the displeasure of the Tsarist regime in Odessa and was restricted to his family estate Mikhaylovskoye in Pskov for two years.
He left Odessa on July 21, 1824, and arrived on August 9.
Writing resumed on September 5, and chapter 3 was finished (apart from stanza XXXVI) on October 2.
The first separate publication of chapter 3 was on October 10, 1827.

Chapter 4 was started in October 1824.
By the end of the year, Pushkin had written 23 stanzas and had reached XXVII by January 5, 1825, at which point he started writing stanzas for Onegin's Journey and worked on other pieces of writing.
He thought that it was finished on September 12, 1825, but later continued the process of rearranging, adding, and omitting stanzas until the first week of 1826.
The first separate edition of chapter 4 appeared with chapter 5 in a publication produced between January 31 and February 2, 1828.

The writing of chapter 5 began on January 4, 1826, and 24 stanzas were complete before the start of his trip to petition the Tsar for his freedom.
He left for this trip on September 4 and returned on November 2, 1826.
He completed the rest of the chapter in the week November 15 to 22, 1826.
The first separate edition of chapter 5 appeared with chapter 4 in a publication produced between January 31 and February 2, 1828.

When Nabokov carried out his study on the writing of Onegin, the manuscript of chapter 6 was lost, but it is known that Pushkin started chapter 6 before finishing chapter 5.
Most of chapter 6 appears to have been written before the beginning of December 19, 1826 when Pushkin returned to Moscow after exile on his family estate.
 Many stanzas appeared to have been written between November 22 and 25, 1826.
On March 23, 1828, the first separate edition of chapter 6 was published.

Pushkin started writing chapter 7 in March 1827, but aborted his original plan for the plot of the chapter and started on a different tack, completing the chapter on November 4, 1828.
The first separate edition of chapter 7 was first printed on March 18, 1836.

Pushkin intended to write a chapter called "Onegin's Journey", which occurred between the events of chapters 7 and 8, and in fact was supposed to be the eighth chapter.
Fragments of this incomplete chapter were published, in the same way that parts of each chapter had been published in magazines before each chapter was first published in a separate edition.
When Pushkin completed chapter 8, he published it as the final chapter and included within its denouement the line nine cantos I have written, still intending to complete
As with many other 19th-century novels, Onegin was written and published serially, with parts of each chapter often appearing in magazines before the first printing of each chapter. Many changes, some small and some large, were made from the first appearance to the final edition during Pushkin's lifetime. The following dates mostly come from Nabokov's study of the photographs of Pushkin's drafts that were available at the time, as well as other people's work on the subject.
The first stanza of chapter 1 was started on May 9, 1823, and except for three stanzas (XXXIII, XVIII, and XIX), the chapter was finished on October 22. The remaining stanzas were completed and added to his notebook by the first week of October 1824. Chapter 1 was first published as a whole in a booklet on February 16, 1825, with a foreword which suggests that Pushkin had no clear plan on how (or even whether) he would continue the novel.
Chapter 2 was started on October 22, 1823 (the date when most of chapter 1 had been finished), and finished by December 8, except for stanzas XL and XXXV, which were added sometime over the next three months. The first separate edition of chapter 2 appeared on October 20, 1826.
Many events occurred which interrupted the writing of chapter 3. In January 1824, Pushkin stopped work on Onegin to work on The Gypsies. Except for XXV, stanzas I–XXXI were added on September 25, 1824. Nabokov guesses that Tatyana's Letter was written in Odessa between February 8 and May 31, 1824. Pushkin incurred the displeasure of the Tsarist regime in Odessa and was restricted to his family estate Mikhaylovskoye in Pskov for two years. He left Odessa on July 21, 1824, and arrived on August 9. Writing resumed on September 5, and chapter 3 was finished (apart from stanza XXXVI) on October 2. The first separate publication of chapter 3 was on October 10, 1827.
Chapter 4 was started in October 1824. By the end of the year, Pushkin had written 23 stanzas and had reached XXVII by January 5, 1825, at which point he started writing stanzas for Onegin's Journey and worked on other pieces of writing. He thought that it was finished on September 12, 1825, but later continued the process of rearranging, adding, and omitting stanzas until the first week of 1826. The first separate edition of chapter 4 appeared with chapter 5 in a publication produced between January 31 and February 2, 1828.
The writing of chapter 5 began on January 4, 1826, and 24 stanzas were complete before the start of his trip to petition the Tsar for his freedom. He left for this trip on September 4 and returned on November 2, 1826. He completed the rest of the chapter in the week November 15 to 22, 1826. The first separate edition of chapter 5 appeared with chapter 4 in a publication produced between January 31 and February 2, 1828.
When Nabokov carried out his study on the writing of Onegin, the manuscript of chapter 6 was lost, but it is known that Pushkin started chapter 6 before finishing chapter 5. Most of chapter 6 appears to have been written before the beginning of December 19, 1826 when Pushkin returned to Moscow after exile on his family estate.  Many stanzas appeared to have been written between November 22 and 25, 1826. On March 23, 1828, the first separate edition of chapter 6 was published.
Pushkin started writing chapter 7 in March 1827, but aborted his original plan for the plot of the chapter and started on a different tack, completing the chapter on November 4, 1828. The first separate edition of chapter 7 was first printed on March 18, 1836.
Pushkin intended to write a chapter called "Onegin's Journey", which occurred between the events of chapters 7 and 8, and in fact was supposed to be the eighth chapter. Fragments of this incomplete chapter were published, in the same way that parts of each chapter had been published in magazines before each chapter was first published in a separate edition. When Pushkin completed chapter 8, he published it as the final chapter and included within its denouement the line nine cantos I have written, still intending to complete
Eugene Onegin