Abbot began his schooling at age five and became interested early in the history of antiquity. After attending Phillips Exeter Academy, he studied at Bowdoin College, from which he graduated in 1840. Then he settled in Cambridge and in 1856 assistant librarian of Harvard University, where he focused on Bible studies and not only carried out revisions, but in 1864 a new edition of the book Holy Living and Dying by Jeremy Taylor newly issued.
In 1869 he received a Doctor of Laws ( LL.D. ) of Yale College in 1872 and a Ph.D. in Religious Studies ( Doctor of Divinity, DD) Harvard University, though he was a layman. He then accepted an appointment as professor at the Faculty of Religious Studies ( Divinity School ) from Harvard University and taught there until his death in criticism and interpretation of the New Testament. In addition to his teaching, he has written important articles for magazines, especially bible critical issues. In addition, he created an extensive bibliography as an appendix to the Critical History of Future Life of Alger and the text output of Constantine Tischendorf.
His most important and last work was an issue for the Authorship of the Fourth Gospel (1880 ). Abbot, who was a Unitarian itself, especially written articles for magazines of this religious community. He also wrote occasional articles for the North American Review and the Journal of the American Oriental Society and also was a member of the American Commission for the revision of the New Testament. His other books include New Discussions of the Trinity and Literature of the Doctrine of a Future Life. In addition, he was editor of Andrews Norton's Statement of the Reasons for not Believing the Doctrines of Trinitarians and the Lamson's Church of the First Three Centuries, as well as other controversial writings discussed and wrote the article on pronunciation of names of Worcester Dictionary.
In addition, he devoted himself to his own library had 5000 volumes and included many rare editions as an extensive collection of editions of the Greek New Testament. After his death, his private library was part of the Library School of Divinity at Harvard University.
On the occasion of his death, the School of Divinity in 1884 issued a Festschrift in his honor.