After graduation from Wesleyan, he spent two years in Yale studying medicine and theology, and sometimes preached in the nearby town of Milford, Connecticut.

On March 13, 1847, White married Jane Isabel Atwater of Homer, who came from Cortland County, New York and was then a teacher in the Sabbath School in Rochester, N.Y.

In September 1847 Moses White and Jane, along with Judson Dwight Collins, arrived in Fuzhou, beginning their missionary work there.

Due to his poor health, Moses White was forced to leave Fuzhou in 1853 for New Haven (his wife Mary also left one year earlier) where he resumed medical studies at Yale and began a medical practice which he continued until the end of his life.

In July 1856, he published in Methodist Quarterly Review his summarizing treatise on Fuzhou dialect The Chinese Language Spoken at Fuh Chau.