Osmon was born in Marlow, New Hampshire. He entered the Wilbraham Wesleyan Academy at the age of fifteen, where soon after he converted to Christianity and was received into the church by Dr. Wilbur Fisk. Osmon was licensed to exhort in his seventeenth year. In 1830 he entered Wesleyan University. He had successfully completed three years at Wesleyan when failing health compelled him to leave the institution. Yet, while in college he also was licensed as a Local Preacher, laboring diligently in that office
Ordained and academic ministry
The Rev. Mr. Baker became a teacher in the seminary at Newbury, Vermont in 1834. He was electedPrincipal of this seminary in 1839. Having resigned the seminary principalship in 1844, the Rev. Mr. Baker was appointed Pastor of the M.E. Church inManchester, New Hampshire. He was appointed Presiding Elder of the Dover District in 1846. During the next year he accepted a professorship in the General Biblical Institute in Concord, New Hampshire, which later became the Boston University School of Theology. Dr. Baker became a distinguished scholar. He also continued to reside in Concord for the remainder of his life.
Episcopal ministry
The Rev. Dr. Osmon Cleander Baker was elected and consecrated to the Episcopacy of the Methodist Episcopal Church by the 1852 General Conference. He discharged the varied duties of this office with diligence and success until 1866. In 1866 Bishop Baker was attacked with partial paralysis while on his way to preside over the ColoradoAnnual Conference. He reached his destination with great difficulty. He thus examined and ordained the ordinands in a private room, rather than before the entire Conference. He then returned home, having suffered much pain and extreme exhaustion. Bishop Baker's health then became sufficiently restored to enable him to preside at a few other Annual Conferences, and to attend the annual and semi-annual meetings of the Board of Bishops of the M.E. Church for two more years, when his strength again declined and his voice was greatly affected.
Death
Bishop Baker was no longer able to take a public role in the work of the church. Nevertheless, he continued to attend the various meetings and enjoyed them, up until a short time before his death. Returning from worship one Sabbath, he fell helpless at the threshold of his home, but regained his strength for a time. The fatal stroke of paralysis came 8 December 1871. Bishop Baker lingered but a few days afterwards. He died 20 December 1871 in Concord, New Hampshire, aged fifty-nine years.