Samson Occom was a Mohegan leader and ordained Presbyterian minister. Occom began his public career in 1742, when he was chosen as a tribal counselor to Ben Uncas II. The following year, he sought out Eleazar Wheelock, a young Anglo-American minister in Lebanon, CT, in hopes of obtaining some education and becoming a teacher at Mohegan. Wheelock agreed to take on Occom as a student, and though Occom had anticipated staying for a few weeks or months, he remained with Wheelock for four years. Occom’s academic success inspired Wheelock to open Moor’s Indian Charity School in 1754, a project which gave him the financial and political capital to establish Dartmouth College in 1769. After his time with Wheelock, Occom embarked on a 12-year mission to the Montauk of Long Island (1749-1761). He married a Montauk woman, Mary Fowler, and served as both teacher and missionary to the Montauk and nearby Shinnecock, although he was grievously underpaid for his services. Occom conducted two brief missions to the Oneida in 1761 and 1762 before embarking on one of the defining journeys of his career: a fundraising tour of Great Britain that lasted from 1765 to 1768. During this journey, undertaken on behalf of Moor’s Indian Charity School, Occom raised £12,000 (an enormous and unanticpated amount that translates roughly to more than two-million dollars), and won wide acclaim for his preaching and comportment. Upon his return to Mohegan in 1768, Occom discovered that Wheelock had failed to adequately care for his family while he was gone. Additionally, despite the vast sums of money that he had raised, Occom found himself unemployed. Wheelock tried to find Occom a missionary position, but Occom was in poor health and disinclined to leave his family again after seeing the treatment with which they had met while he was in Britain. Occom and Wheelock’s relationship continued to sour as it became apparent to Occom that the money he had labored to raise would be going towards infrastructure at Dartmouth College, Wheelock’s new project, rather than the education of Native Americans. After the dissolution of his relationship with Wheelock, Occom became increasingly focused on the needs of the Mohegan community and increasingly vocal in criticizing Anglo-Americans’ un-Christian treatment of Native Americans. In September of 1772, he delivered his famous “Sermon on the Execution of Moses Paul,” which took Anglo-American spiritual hypocrisy as one of its major themes, and which went into four printings before the end of the year. In 1773, Occom became further disillusioned when the Mason Land Case was decided in favor of the Colony of Connecticut. The details of the Mason Case are complicated, but to summarize: the Colony of Connecticut had gained control of Mohegan land early in the 18th century under very suspect circumstances, and successfully fended off the Mohegan’s 70-year-long legal challenge. The conclusion of the case came as a blow to the Mohegans, and further convinced Occom of Anglo-American corruption. Along with David Fowler (Montauk Tribe), Occom's brother-in-law, and Joseph Johnson (Mohegan), Occom's son-in-law, Occom helped found Brothertown, an Indian tribe formed from the Christian Mohegans, Pequots, Narragansetts, Montauks, Tunxis, and Niantics. They eventually settled in Oneida country in upstate New York. Occom moved there with his family in 1789, spending the remaining years of his life serving as a minster to the Brothertown, Stockbridge, and Mohegan Indians. Harried by corrupt land agents, the Brothertown and Stockbridge groups relocated to the eastern shore of Lake Winnebago, though Occom died in 1792 before he could remove himself and his family there. Occom's writings and legacy have made him one of the best known and most eminent Native Americans of the 18th century and beyond.

Robert Clelland was the Scottish schoolmaster at Mohegan who became a contentious figure. He began as schoolmaster in 1752, supported by the Boston commissioners of the Society in Scotland for Propagating Christian Knowledge. Clelland resided in an apartment that was either adjacent or close to the school, and although he had a limited income, the Colony provided him with bread daily. Clelland had a close relationship with Reverend David Jewett, the white minister at Mohegan who oversaw the school and often lectured there; both Clelland and Jewett supported Connecticut in the Mason Case. However, Clelland conflicted with many other leaders in Mohegan. He repeatedly wrote to Eleazar Wheelock complaining about Ben Uncas III and his drunkenness, even though the sachem did not oppose the colony in the Mason Case and Clelland typically supported him. Clelland also developed a hostile relationship with Samson Occom; notably they held opposing positions during the Mason Case. Occom brought concerns regarding Clelland to the commissioners’ attention. He claimed the schoolteacher preferred the paying English students to the point that their presence was displacing Mohegan pupils, and criticized other ways in which Clelland ran the school. On September 19, 1764, the commissioners voted to release Clelland of his duties as schoolmaster. Notwithstanding, he remained until he was dismissed again on July 5, 1765. Occom’s involvement with Clelland’s dismissal further disrupted what was already a contentious relationship between him and Jewett. Clelland appears to have remained in Mohegan even after his dismissal.