[5] His first education was in Latin and Greek and he began attendance at a classical school directed by Louis Marshall in Woodford County, Kentucky, at the age of thirteen.

[2] Green took brief interest in law and medicine following his graduation, studying the former with his brother, John, and the latter with physician Ephraim McDowell, each for a short time.

[2] Green went on to study the Hebrew language at Yale College and enrolled at the Princeton Theological Seminary in 1831, where he was a classmate of Henry Augustus Boardman.

[9] Green was first given a chance to enter academia when he was elected professor of Greek at Centre College in August 1831, though he declined the position in order to study at Princeton, where he had just enrolled.

[10] In August 1834, some months after his marriage to Mary Lawrence, he obtained a two-year leave of absence from Centre and sailed with his wife from New York to Liverpool in order to learn more about, and improve his skills in, the ministry; they arrived on September 15, 1834.

The pair spent two weeks in London before traveling to Berlin, and Green heard lectures from August Neander and Ernst Wilhelm Hengstenberg.

[11] In mid-1835 they traveled throughout Germany and Switzerland and Green spent the following winter in Haale studying under August Tholuck, Karl Ullmann, and Wilhelm Gesenius.

[12] Green was offered the pastorate of the Presbyterian Church of Shelbyville, Kentucky, after preaching a sermon there in 1837, though he declined in order to remain at Centre.

[2] In May 1840, Green was called away from Kentucky once again after the Presbyterian General Assembly unanimously appointed him professor of oriental literature and biblical criticism at Western Theological Seminary,[2] on the recommendation of Charles Stewart Todd.

[17][18] He originally planned to have them sent to Liberia with the help of the American Colonization Society, but when they were not willing to go, Green freed them and allowed them to remain in the United States.

[22] In mid-1848, Green was invited to speak at Hampden–Sydney College; at that time, the trustees were considering him for the school's presidency,[23] which had been left vacant by Patrick J. Sparrow in 1847.

[39] The Hampden–Sydney board of trustees were unsuccessful in convincing him to stay—one strategy involved the proposal of a 50% salary increase[18]—and he resigned the presidency of Hampden–Sydney upon his return to Virginia.

In March 1856, the Kentucky General Assembly passed an act which reorganized Transylvania, established a normal school there, and gave the college a new board of trustees.

[47] He concluded his first year at Transylvania on June 24, 1857, and the large crowd present at commencement that day was seen by local press as a promising sign that the school might be leaving its recent struggles behind.

[48] This changed during the ensuing General Assembly winter session, during which the bill which had established the normal school was repealed by a large majority.

[49] As the now-dissolved normal school was among the main reasons Green had gone to Transylvania, he resigned in late 1857 and formally left the position January 1, 1858.

[47][50] Green was elected president of Centre College on August 6, 1857, and officially assumed office on January 1, 1858, succeeding John C. Young.

[55] On October 9,[54] the day after the Battle of Perryville took place about 12 miles (20 km) from Centre,[55] there were only six students on campus and the faculty decided to cease holding classes and suspend college operations.

Classes were held in the new library, a project completed earlier that year, since Old Centre, the college's main building, was still occupied and being used, in part, as a hospital.

[54] Old Centre's capacity as a hospital was around 150 and the rooms functioning as such were not physically separated from the parts of the building involved with college operations; some students had to pass through autopsies in progress on their way to a professor's office.

[56] During this time, Green continued to preach and teach classes in the place of several absent professors, though not without some physical trouble caused by overwork, his weakened immune system, and the conditions at Centre during the war.

At the time of their marriage, Montgomery was suffering from an "advanced stage" of tuberculosis, according to the biographer Leroy Halsey,[58] and the couple were married for slightly longer than two years before she died in 1829.

[62] Sometime after moving back to Kentucky following his term at Hampden–Sydney, Green increased his enslaved workforce; he held ten people as slaves during his time as Centre president.