Dr. Beriah Frazier set up his medical practice in Hamilton County, first practicing near Harrison.  There he met Cynthia Mynatt, whose twin brother, J.C. Mynatt, was the clerk and master.  Dr. Frazier and Cynthia Mynatt were married at Knoxville in 1841.  He is said to be the only Chattanooga mayor to have married during his term in office.

Dr. Frazier was an elder in the city's Presbyterian Church and he was junior warden of Chattanooga's first Masonic lodge. But he decided to move to Knoxville, and he was living there at a farm on Beaver Creek at the time of the Civil War.

Dr. Frazier was a delegate from Knox County to the East Tennessee Union Convention that met in Knoxville in May of 1861.  Just after the war, the Unionist was a state senator from Knox County.  He was later a trustee of East Tennessee University (University of Tennessee) and was president of the Tazewell Pike Company.

Dr. Frazier had partially completed a history of the Civil War at the time of his death in 1886. Cynthia Mynatt Frazier died in 1880.  Dr. Frazier had no children.