The Tennessee Vital Records Office keeps birth records for 100 years; after that they are available for public access through the Tennessee State Library and Archives. Thus, TSLA has statewide Tennessee birth records for the years 1908-1912 and 1914-1918. No birth records were recorded at the state level in 1913; also, initial adoption was spotty. Copies of available records can be ordered from TSLA, with instructions found on this web page – Ordering Birth Certificates. Birth records from 1919 to the present can be obtained from the Tennessee Department of Health, Office of Vital Records. Restrictions and fees apply, so be sure to check the web site.
Other places to look for birth information are the Tennessee Births and Christenings, 1828-1939 index available at Family Search, as well as newspapers and bible records.