His father's professional concerns for his parishioners left Birch with much time on his own, and he often raised small amounts of money for himself by picking up soft drink bottles for their deposit values, and generally learned to function independently.

He then attended Howard University in Washington, where he earned the Bachelor of Arts and Doctor of Jurisprudence degrees, serving on the law review 1954-56 and graduating in 1956.

[2] In the early 1960s he provided volunteer legal representation to civil rights activists who had been arrested for conducting sit-ins at segregated lunch counters.

In 1966, he was appointed assistant district attorney for Davidson County, a full-time position which required him to end his private law practice.

[3] In 1969, Governor Buford Ellington appointed him as a General Sessions Court judge in Davidson County, making him the first African American to serve in that office.

[3] In 1978 he was appointed Criminal Court Judge for the Twentieth District (Davidson County) by Governor Ray Blanton.

Birch served in this position until 1987; in 1981-82 he was the presiding judge over the Trial Courts of Davidson County, making him responsible for case assignment and other procedural issues.